[opensuse] How to connect two servers through an Ethernet A/B switch and not change the upstream MAC addy?
Hi Folks, I've got an interesting network configuration problem that I'd like to run by you all. At this time I've got a server that connects to a switch at 1GbE over Cat-6 copper with RJ-45 connections. I don't have admin rights on the switch and it uses MAC address authentication to turn on the port. The server is rather important and contains about 400-TB of data in multiple RAID-6 arrays. I've received authorization to purchase a second "mirror" server to act as a warm spare. They will have a private 192.168 subnet via second Ethernet ports, maybe 10GbE, to synchronize the data on a regular basis between the servers. What's the best way to hook these up? I'm thinking of something like an RJ-45 A/B switch to manually connect one or the other server to the upstream switch. But then, it looks like simple switches just pass through the two back MAC addresses, and I need the A/B switch to present the same MAC to upstream at all times. Could I use macchanger on each of the servers to keep the same MAC presented through the switch? Or is there a better way? Thanks, Lew -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Lew Wolfgang wrote:
Hi Folks,
I've got an interesting network configuration problem that I'd like to run by you all.
At this time I've got a server that connects to a switch at 1GbE over Cat-6 copper with RJ-45 connections. I don't have admin rights on the switch and it uses MAC address authentication to turn on the port.
The server is rather important and contains about 400-TB of data in multiple RAID-6 arrays. I've received authorization to purchase a second "mirror" server to act as a warm spare. They will have a private 192.168 subnet via second Ethernet ports, maybe 10GbE, to synchronize the data on a regular basis between the servers.
So not a hot standby, more like a backup copy, but always fairly recent?
What's the best way to hook these up?
First thought - just a cross-over cable between two interfaces. Or multiple bonded ditto. That's how we run our storage servers with drbd.
I'm thinking of something like an RJ-45 A/B switch to manually connect one or the other server to the upstream switch. But then, it looks like simple switches just pass through the two back MAC addresses, and I need the A/B switch to present the same MAC to upstream at all times.
As you have funding for purchasing a secon d server, might it not be feasible to have the 2nd MAC authorised on the upstream switch? -- Per Jessen, Zürich (15.6°C) http://www.cloudsuisse.com/ - your owncloud, hosted in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2019-06-10 03:35 AM, Per Jessen wrote:
First thought - just a cross-over cable between two interfaces. Or multiple bonded ditto. That's how we run our storage servers with drbd.
Crossover cables are only needed with 10 & 100 Mb. Gigabit & 10G use all 4 pairs in both directions. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
James Knott wrote:
On 2019-06-10 03:35 AM, Per Jessen wrote:
First thought - just a cross-over cable between two interfaces. Or multiple bonded ditto. That's how we run our storage servers with drbd.
Crossover cables are only needed with 10 & 100 Mb. Gigabit & 10G use all 4 pairs in both directions.
The latter I knew, but it had not occurred to me that it would eliminate the need for a cross-over cable. Thanks. -- Per Jessen, Zürich (15.1°C) http://www.cloudsuisse.com/ - your owncloud, hosted in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2019-06-10 08:48 AM, Per Jessen wrote:
James Knott wrote:
First thought - just a cross-over cable between two interfaces. Or multiple bonded ditto. That's how we run our storage servers with drbd. Crossover cables are only needed with 10 & 100 Mb. Gigabit & 10G use all 4 pairs in both directions. The latter I knew, but it had not occurred to me that it would eliminate
On 2019-06-10 03:35 AM, Per Jessen wrote: the need for a cross-over cable. Thanks.
Even at 100 Mb, newer equipment can often automagically detect what's at the other end. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
James Knott wrote:
On 2019-06-10 08:48 AM, Per Jessen wrote:
James Knott wrote:
On 2019-06-10 03:35 AM, Per Jessen wrote:
First thought - just a cross-over cable between two interfaces. Or multiple bonded ditto. That's how we run our storage servers with drbd. Crossover cables are only needed with 10 & 100 Mb. Gigabit & 10G use all 4 pairs in both directions. The latter I knew, but it had not occurred to me that it would eliminate the need for a cross-over cable. Thanks.
Even at 100 Mb, newer equipment can often automagically detect what's at the other end.
Yes lots of switches do auto-switching, but I'm not sure if I've seen network cards do it too. -- Per Jessen, Zürich (15.1°C) http://www.cloudsuisse.com/ - your owncloud, hosted in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 06/10/2019 12:35 AM, Per Jessen wrote:
Lew Wolfgang wrote:
Hi Folks,
I've got an interesting network configuration problem that I'd like to run by you all.
At this time I've got a server that connects to a switch at 1GbE over Cat-6 copper with RJ-45 connections. I don't have admin rights on the switch and it uses MAC address authentication to turn on the port.
The server is rather important and contains about 400-TB of data in multiple RAID-6 arrays. I've received authorization to purchase a second "mirror" server to act as a warm spare. They will have a private 192.168 subnet via second Ethernet ports, maybe 10GbE, to synchronize the data on a regular basis between the servers. So not a hot standby, more like a backup copy, but always fairly recent?
Yes, maybe sync the deltas from the active box to the standby every six hours or so? Maybe even daily would work okay. The really dynamic function being served is Subversion. Users would still have local checked-out copies of their data if something went wrong. svnserve has a nifty script that does hot-backups of repositories, and I think it could even be configured to automatically replicate onto a second server. I'd have to play around with that one.
What's the best way to hook these up? First thought - just a cross-over cable between two interfaces. Or multiple bonded ditto. That's how we run our storage servers with drbd.
Yes, the servers have two Ethernet interfaces, one will connect to a back-end subnet for syncing/backups. There are some other servers back there that never leave the 192.168.4.0/24 subnet. NAT is not used, there's no IP forwarding going on.
I'm thinking of something like an RJ-45 A/B switch to manually connect one or the other server to the upstream switch. But then, it looks like simple switches just pass through the two back MAC addresses, and I need the A/B switch to present the same MAC to upstream at all times. As you have funding for purchasing a secon d server, might it not be feasible to have the 2nd MAC authorised on the upstream switch?
Yes, a second MAC and port could be used, but then each server would have different IP addresses. We've got about 100 local users using svnserve, samba, NFS, and direct ssh logins, and we need to be able to quickly switch between the two servers transparently. A DNS CNAME could be used, but the switch time would depend on caches timing out. I wouldn't think that switching would happen very often, but it would be nice if it could be locally deterministic. A smooth transition would involved shutting down the active interface on A, then do a delta data-sync to the B via the back-end interfaces, then switch upstream from A to B, then bring up B's interface. I think this could be done with "macchanger", but I've never fiddled with it. Of course, a sudden failure of A, with subsequent switching to B, would be messier and possibly loose data, but such is life. At least the whole system wouldn't be down for an extended period of time. Regards, Lew -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On Mon, 10 Jun 2019 07:46:30 -0700 Lew Wolfgang <wolfgang@sweet-haven.com> wrote:
Yes, a second MAC and port could be used, but then each server would have different IP addresses.
Not so, it's a lot easier to use the same IP address for the two machines if only one will be connected at any time. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 6/10/19 9:12 AM, Dave Howorth wrote:
On Mon, 10 Jun 2019 07:46:30 -0700 Lew Wolfgang <wolfgang@sweet-haven.com> wrote:
Yes, a second MAC and port could be used, but then each server would have different IP addresses. Not so, it's a lot easier to use the same IP address for the two machines if only one will be connected at any time.
Yes, I agree. But upstream, over which I have no control, maps IP addresses with MAC addresses. Also, static IP's aren't allowed, DHCP only. It's also a dual-stack v4/v6 network, which complicates things. Regards, Lew -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Lew Wolfgang wrote:
On 6/10/19 9:12 AM, Dave Howorth wrote:
On Mon, 10 Jun 2019 07:46:30 -0700 Lew Wolfgang <wolfgang@sweet-haven.com> wrote:
Yes, a second MAC and port could be used, but then each server would have different IP addresses. Not so, it's a lot easier to use the same IP address for the two machines if only one will be connected at any time.
Yes, I agree. But upstream, over which I have no control, maps IP addresses with MAC addresses.
This is not just ARP I take it?
Also, static IP's aren't allowed, DHCP only. It's also a dual-stack v4/v6 network, which complicates things.
Presumably you have DHCP clients on your primary ond your standby? That's fine, but if you can't reserve one fixed address, that makes a bit more problematic. The dual stack does not matter. -- Per Jessen, Zürich (16.1°C) http://www.hostsuisse.com/ - virtual servers, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 6/10/19 11:01 AM, Per Jessen wrote:
Lew Wolfgang wrote:
On 6/10/19 9:12 AM, Dave Howorth wrote:
On Mon, 10 Jun 2019 07:46:30 -0700 Lew Wolfgang <wolfgang@sweet-haven.com> wrote:
Yes, a second MAC and port could be used, but then each server would have different IP addresses. Not so, it's a lot easier to use the same IP address for the two machines if only one will be connected at any time. Yes, I agree. But upstream, over which I have no control, maps IP addresses with MAC addresses. This is not just ARP I take it?
Correct, not just ARP.
Also, static IP's aren't allowed, DHCP only. It's also a dual-stack v4/v6 network, which complicates things. Presumably you have DHCP clients on your primary ond your standby? That's fine, but if you can't reserve one fixed address, that makes a bit more problematic. The dual stack does not matter.
Yes, the servers run DHCP clients. I use dnsmasq to control the private subnet behind the servers. Yes, I can't reserve a static IP addy. MAC addresses are manually entered into an LDAP database which is used to open a switch port when that MAC appears on a port. The DHCP-dispensed IP addy comes from that same LDAP database. Regards, Lew -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Lew Wolfgang wrote:
On 6/10/19 11:01 AM, Per Jessen wrote:
Lew Wolfgang wrote:
On 6/10/19 9:12 AM, Dave Howorth wrote:
On Mon, 10 Jun 2019 07:46:30 -0700 Lew Wolfgang <wolfgang@sweet-haven.com> wrote:
Yes, a second MAC and port could be used, but then each server would have different IP addresses. Not so, it's a lot easier to use the same IP address for the two machines if only one will be connected at any time. Yes, I agree. But upstream, over which I have no control, maps IP addresses with MAC addresses. This is not just ARP I take it?
Correct, not just ARP.
Also, static IP's aren't allowed, DHCP only. It's also a dual-stack v4/v6 network, which complicates things. Presumably you have DHCP clients on your primary ond your standby? That's fine, but if you can't reserve one fixed address, that makes a bit more problematic. The dual stack does not matter.
Yes, the servers run DHCP clients. I use dnsmasq to control the private subnet behind the servers.
Yes, I can't reserve a static IP addy. MAC addresses are manually entered into an LDAP database which is used to open a switch port when that MAC appears on a port. The DHCP-dispensed IP addy comes from that same LDAP database.
Okay, so the usual method is out. Hmm, any reason why you couldn't put a box between the upstream and your two servers? I am thinking of using LVS, but you're going to need to a fixed address. Unless you would want to redefine the LVS setup on every change of address. Actually, that could work. Put a box between upstream and your two storage boxes. This box gets a DCHP address from upstream, your storage boxes have fixed IPs, private network. The LVS setup has to be reconfigured if the address changes, but that's doable. -- Per Jessen, Zürich (15.4°C) http://www.cloudsuisse.com/ - your owncloud, hosted in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 6/10/19 11:29 AM, Per Jessen wrote:
Lew Wolfgang wrote:
On 6/10/19 11:01 AM, Per Jessen wrote:
Lew Wolfgang wrote:
On 6/10/19 9:12 AM, Dave Howorth wrote:
On Mon, 10 Jun 2019 07:46:30 -0700 Lew Wolfgang <wolfgang@sweet-haven.com> wrote:
Yes, a second MAC and port could be used, but then each server would have different IP addresses. Not so, it's a lot easier to use the same IP address for the two machines if only one will be connected at any time. Yes, I agree. But upstream, over which I have no control, maps IP addresses with MAC addresses. This is not just ARP I take it? Correct, not just ARP.
Also, static IP's aren't allowed, DHCP only. It's also a dual-stack v4/v6 network, which complicates things. Presumably you have DHCP clients on your primary ond your standby? That's fine, but if you can't reserve one fixed address, that makes a bit more problematic. The dual stack does not matter. Yes, the servers run DHCP clients. I use dnsmasq to control the private subnet behind the servers.
Yes, I can't reserve a static IP addy. MAC addresses are manually entered into an LDAP database which is used to open a switch port when that MAC appears on a port. The DHCP-dispensed IP addy comes from that same LDAP database. Okay, so the usual method is out.
Hmm, any reason why you couldn't put a box between the upstream and your two servers? I am thinking of using LVS, but you're going to need to a fixed address. Unless you would want to redefine the LVS setup on every change of address. Actually, that could work. Put a box between upstream and your two storage boxes. This box gets a DCHP address from upstream, your storage boxes have fixed IPs, private network. The LVS setup has to be reconfigured if the address changes, but that's doable.
Now that's a thought, I'll have to stew on that one. I've never used LVS and will have to brush up a bit. Thanks Per. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On Mon, 10 Jun 2019 10:10:47 -0700 Lew Wolfgang <wolfgang@sweet-haven.com> wrote:
On 6/10/19 9:12 AM, Dave Howorth wrote:
On Mon, 10 Jun 2019 07:46:30 -0700 Lew Wolfgang <wolfgang@sweet-haven.com> wrote:
Yes, a second MAC and port could be used, but then each server would have different IP addresses. Not so, it's a lot easier to use the same IP address for the two machines if only one will be connected at any time.
Yes, I agree. But upstream, over which I have no control, maps IP addresses with MAC addresses. Also, static IP's aren't allowed, DHCP only. It's also a dual-stack v4/v6 network, which complicates things.
If the IP addresses are dynamically assigned, and changeable, I can't see why they matter, or the MAC addresses for that matter? I mean whoever is connecting to the server certainly isn't doing it using the MAC address, and seemingly can't be doing it using the IP address if that can change, so presumably is using something like a DNS address? In which case, why not change the address map so that the DNS points to whichever IP is currently online? There must be some method to do that if the IP address can vary arbitrarily. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2019-06-10 03:16 PM, Dave Howorth wrote:
or the MAC addresses for that matter?
I believe the OP mentioned switch port security, where only specific MAC addresses are allowed on a given port. That's to keep people from plugging foreign devices into the network. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On Mon, 10 Jun 2019 15:18:47 -0400 James Knott <james.knott@jknott.net> wrote:
On 2019-06-10 03:16 PM, Dave Howorth wrote:
or the MAC addresses for that matter?
I believe the OP mentioned switch port security, where only specific MAC addresses are allowed on a given port. That's to keep people from plugging foreign devices into the network.
Yes, I know that but that's a purely local issue. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Lew Wolfgang wrote:
On 06/10/2019 12:35 AM, Per Jessen wrote:
Lew Wolfgang wrote:
Hi Folks,
I've got an interesting network configuration problem that I'd like to run by you all.
At this time I've got a server that connects to a switch at 1GbE over Cat-6 copper with RJ-45 connections. I don't have admin rights on the switch and it uses MAC address authentication to turn on the port.
The server is rather important and contains about 400-TB of data in multiple RAID-6 arrays. I've received authorization to purchase a second "mirror" server to act as a warm spare. They will have a private 192.168 subnet via second Ethernet ports, maybe 10GbE, to synchronize the data on a regular basis between the servers. So not a hot standby, more like a backup copy, but always fairly recent?
Yes, maybe sync the deltas from the active box to the standby every six hours or so? Maybe even daily would work okay.
Much depends on the purpose of the standby - how up-to-date the information has to be.
Yes, a second MAC and port could be used, but then each server would have different IP addresses.
Not necessarily - as in a high-availability setup, you could assign a 2nd IP address that moves between the primary and the standby. So you might have 192.168.123.1 (primary) and 192.168.123.2 (standby) and 192.168.123.99 as server address.
We've got about 100 local users using svnserve, samba, NFS, and direct ssh logins, and we need to be able to quickly switch between the two servers transparently.
I would say a moving IP address is what you need. -- Per Jessen, Zürich (17.4°C) http://www.cloudsuisse.com/ - your owncloud, hosted in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 6/10/19 9:33 AM, Per Jessen wrote:
We've got about 100 local users using svnserve, samba, NFS, and direct ssh logins, and we need to be able to quickly switch between the two servers transparently. I would say a moving IP address is what you need.
But that would require those 100 users to change their various client configurations to track which server is on-line. You know how users are, imagine the chaos! Most of them are Windows users too! A CNAME pointing to the active server would work, except for the stale cache time. I may have to fiddle around with this option, it would be much cleaner to have both servers connected with their own IP addresses and hostnames, then do the switching by changing the CNAME hostname. Scheduled switches could happen at night, unscheduled failures maybe could be tolerated until the DNS cache times out. Regards, Lew -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
10.06.2019 20:24, Lew Wolfgang пишет:
On 6/10/19 9:33 AM, Per Jessen wrote:
We've got about 100 local users using svnserve, samba, NFS, and direct ssh logins, and we need to be able to quickly switch between the two servers transparently. I would say a moving IP address is what you need.
But that would require those 100 users to change their various client configurations to track which server is on-line.
No, it won't. They will continue to use the same IP address. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 6/10/19 10:27 AM, Andrei Borzenkov wrote:
10.06.2019 20:24, Lew Wolfgang пишет:
On 6/10/19 9:33 AM, Per Jessen wrote:
We've got about 100 local users using svnserve, samba, NFS, and direct ssh logins, and we need to be able to quickly switch between the two servers transparently. I would say a moving IP address is what you need. But that would require those 100 users to change their various client configurations to track which server is on-line. No, it won't. They will continue to use the same IP address.
But the well-known IP address is tied to only one of the server's via its MAC. The upstream network maps IP's to MAC's, so to have a static IP I'd need a static MAC. I've got only low-level web-based access to the DNS system, which limits my options. The most reliable method would have users not using IP's or A-record hostnames, but only a CNAME that can be changed as needed. There's only that pesky DNS cache timeout to worry about, as I understand things. I can remap the CNAME myself, but have no access to deeper things. Regards, Lew -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Lew Wolfgang wrote:
On 6/10/19 10:27 AM, Andrei Borzenkov wrote:
10.06.2019 20:24, Lew Wolfgang пишет:
On 6/10/19 9:33 AM, Per Jessen wrote:
We've got about 100 local users using svnserve, samba, NFS, and direct ssh logins, and we need to be able to quickly switch between the two servers transparently. I would say a moving IP address is what you need. But that would require those 100 users to change their various client configurations to track which server is on-line. No, it won't. They will continue to use the same IP address.
But the well-known IP address is tied to only one of the server's via its MAC. The upstream network maps IP's to MAC's, so to have a static IP I'd need a static MAC. I've got only low-level web-based access to the DNS system, which limits my options.
"The upstream network maps IP's to MAC's," - what does that mean? You have two static MAC addresses, each has a fixed address, and one address can move between them, by way of ARP. It's a perfectly normal HA setup.
The most reliable method would have users not using IP's or A-record hostnames, but only a CNAME that can be changed as needed.
What is wrong with giving your users a servername = lew.example.com = 192.168.123.99 As the address is assigned on the primary, they go to the primary. When the address is assigned on the standby .... It sounds like there is a restriction in your network that we don't know about? -- Per Jessen, Zürich (15.8°C) http://www.cloudsuisse.com/ - your owncloud, hosted in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2019-06-09 11:58 PM, Lew Wolfgang wrote:
I'm thinking of something like an RJ-45 A/B switch to manually connect one or the other server to the upstream switch. But then, it looks like simple switches just pass through the two back MAC addresses, and I need the A/B switch to present the same MAC to upstream at all times. Could I use macchanger on each of the servers to keep the same MAC presented through the switch?
Or is there a better way?
Well, you could use MAC spoofing, assuming the hardware supports it, but the proper solution is to get whoever to configure the switch to allow the new server. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 06/09/2019 10:58 PM, Lew Wolfgang wrote:
Hi Folks,
I've got an interesting network configuration problem that I'd like to run by you all.
At this time I've got a server that connects to a switch at 1GbE over Cat-6 copper with RJ-45 connections. I don't have admin rights on the switch and it uses MAC address authentication to turn on the port.
The server is rather important and contains about 400-TB of data in multiple RAID-6 arrays. I've received authorization to purchase a second "mirror" server to act as a warm spare. They will have a private 192.168 subnet via second Ethernet ports, maybe 10GbE, to synchronize the data on a regular basis between the servers.
What's the best way to hook these up?
I'm thinking of something like an RJ-45 A/B switch to manually connect one or the other server to the upstream switch. But then, it looks like simple switches just pass through the two back MAC addresses, and I need the A/B switch to present the same MAC to upstream at all times. Could I use macchanger on each of the servers to keep the same MAC presented through the switch?
Or is there a better way?
I am no network export, so take this for what it is worth, but from a couple of decades of playing with a number of switches, DNS, etc.., I would think something like the following would be possible in this situation. +-------------------------+ | switch you can't change | +-------------------------+ | +--------------------+--------------------+ | | | | +-------------------------+ | | | smart switch providing | | | | port aggregation with | | Seen as single | | mac address cloning | | unit with | | from server A | | failover | +-------------------------+ | between A -> B | | | | to upstream | +------------+ +------------+ | switch | | server A | | server B | | | +------------+ +------------+ | +-----------------------------------------+ The port aggregation can make A / B be treated as a single unit even though they have independent IP address at the aggregating switch. It should be able to clone the Mac address from A and put that forward as the Mac for that link. The failover from A / B can be done several ways, either the switch will be smart enough to handle a primary/backup role for A / B and handle it there, some type of old box DNS between A / B and the aggregating switch handling failover for IPs in the aggregated link should work. What I don't know is how expensive a switch it will take to do it. Some of the $120-$150 consumer grade models can do the link aggregation and IIRC limited failover. If the switch can't handle failover, putting a box running bind between A / B and the switch that can do it for you at that level. I'm sure your higher-end switch/router hardware provides a lot more capability that I haven't even run across yet. The bigger challenge would seem to be replication between A / B in near real-time to B so B can pickup from A on failover without much if any loss of data. (open/temporary documents might be a problem, but hardware raid with battery powered write-back cache that can be replicated on B may be a way to mitigate against that to some extent) That about exhausts the educated guess I would have as a way to research putting the puzzle together. Remember, it's all elementary until you pull the power cord on A to see if it works :) -- David C. Rankin, J.D.,P.E. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
participants (6)
-
Andrei Borzenkov -
Dave Howorth -
David C. Rankin -
James Knott -
Lew Wolfgang -
Per Jessen