pppd sporadically uses ppp1 instead of ppp0

Hi I'm using SuSE 7.3 as a firewall accessing the IN via DSL. By chance I found in the archived /var/message files of the last months that pppd sporadically connects thru ppp1 instead of ppp0: messages:Apr 13 12:11:37 xxxxxx pppd[6215]: Using interface ppp1 messages:Apr 13 12:11:37 xxxxxx pppd[6215]: Connect: ppp1 <--> /dev/pts/1 messages:Jan 18 15:51:36 xxxxxx pppd[2511]: Using interface ppp1 messages:Jan 18 15:51:36 xxxxxx pppd[2511]: Connect: ppp1 <--> /dev/pts/2 Since my firewall rules are bound to ppp0 my firewall box has been unshielded, right? As a workaround I have blocked all traffic thru ppp1, ppp2, ppp3. Questions: a) How do I ensure that pppd only takes ppp0? b) Do ppp2, ppp3 etc. exist? Best regards Peter