Is it possible to telnet reliably to a computer that has gotten its IP address via DHCP? My assumption is that it isn't, since telnet seems to require a specific IP address and the DHCP one can change. But I'd like to be shown to be wrong. That seems to be a disadvantage of using DHCP to assign IP addresses. Paul Abrahams
Paul W. Abrahams wrote:
Is it possible to telnet reliably to a computer that has gotten its IP address via DHCP? My assumption is that it isn't, since telnet seems to require a specific IP address and the DHCP one can change. But I'd like to be shown to be wrong.
That seems to be a disadvantage of using DHCP to assign IP addresses.
Contact your DHCP administrator and ask if they can staticly assign an IP address to the MAC address of your NIC. This is a policy issue at your site as to whether they will do that. That's the best option for reliability. Practically speaking, if you boot the machine on a regular basis, you can count on getting the same address over and over. This depends on how the DHCP server is configured and how congested the pool is. Chris...
On Friday 12 March 2004 21:34, Paul W. Abrahams wrote:
Is it possible to telnet reliably to a computer that has gotten its IP address via DHCP? My assumption is that it isn't, since telnet seems to require a specific IP address and the DHCP one can change. But I'd like to be shown to be wrong.
That seems to be a disadvantage of using DHCP to assign IP addresses.
Paul Abrahams
A dynamic address is not unreliable per se, it's all about how the DHCP server is configured. (This does not go for Mickeysoft computers, since M$ has never managed to make a decent IP stack .. = :-/ IMHO. OK, they have improved _slightly_ in 2k and XP, though, but I've abandoned that ship). Under normal circumstances the address should remain the same "forever", or at least as long as the server/host is powered up and connected to the network, since it will always reclaim the same address. However, if the lease time is very short and almost all addresses are in use, the server might get a different address if it's been down for a while. My recommendation is to have DHCP-distributed dedicated addresses for servers. (Assuming that you have access to the DHCP-server or at least that you can give the administrator a hint.) The reason for that is that DHCP works like a sort of "network registration" which is useful if you're having problems and need to do troubleshooting. /Marty
Paul W. Abrahams wrote:
Is it possible to telnet reliably to a computer that has gotten its IP address via DHCP? My assumption is that it isn't, since telnet seems to require a specific IP address and the DHCP one can change. But I'd like to be shown to be wrong.
That seems to be a disadvantage of using DHCP to assign IP addresses.
Unless the address is changing frequently, dhcp shouldn't be a problem. My address is so stable, it's virtually static. Also, if you have a stable host name, you don't even have to worry about the IP address. Even if your address changes regularly, along with the host name, you can still use one of those dynamic dns services or just have your Linux firewall e-mail you, whenever the IP address changes. Incidentally, I regularly connect to my network via vpn or ssh, without problem.
On Friday 12 March 2004 10:34, Paul W. Abrahams wrote:
Is it possible to telnet reliably to a computer that has gotten its IP address via DHCP? My assumption is that it isn't, since telnet seems to require a specific IP address and the DHCP one can change. But I'd like to be shown to be wrong.
That seems to be a disadvantage of using DHCP to assign IP addresses.
Paul Abrahams
See this: http://www.dyndns.org/ -- _____________________________________ John Andersen
participants (5)
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Chris Trown -
James Knott -
John Andersen -
Paul W. Abrahams -
Smartyone