i have a reproducable situation where the system responds to pings on an
interface that does not show up in ifconfig. i'm running 2.2.14 on i386.
the machine (let's call her borealis) has two interfaces. eth0 is connected
to a local network (192.168.1.1), eth1 is connected to a dsl modem with a
static ip (140.186.109.11). until recently, we were using ppp/ipmasq in
place of eth1. i expect this to be a not uncommon setup.
if i bring eth1 (dsl) down, i can still ping (even ssh in) on that interface
from borealis or one of the machines she masquerades for (nothing).
borealis:~# ifup eth1
borealis:~# ifconfig
eth0 Link encap:Ethernet HWaddr 00:60:67:44:A8:BF
inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1713 errors:0 dropped:0 overruns:0 frame:0
TX packets:1721 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
Interrupt:10 Base address:0xec00
eth1 Link encap:Ethernet HWaddr 00:80:C8:59:07:5F
inet addr:140.186.109.11 Bcast:140.186.255.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:351 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
Interrupt:11 Base address:0xec80
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:3924 Metric:1
RX packets:120 errors:0 dropped:0 overruns:0 frame:0
TX packets:120 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
borealis:~# ssh jake@nothing ping -c 4 140.186.109.11
jake@nothing.megabite.net's password:
PING 140.186.109.11 (140.186.109.11): 56 data bytes
64 bytes from 140.186.109.11: icmp_seq=0 ttl=255 time=0.2 ms
64 bytes from 140.186.109.11: icmp_seq=1 ttl=255 time=0.2 ms
64 bytes from 140.186.109.11: icmp_seq=2 ttl=255 time=0.2 ms
64 bytes from 140.186.109.11: icmp_seq=3 ttl=255 time=0.2 ms
--- 140.186.109.11 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.2/0.2/0.2 ms
Connection to nothing.megabite.net closed.
borealis:~# ifdown eth1
borealis:~# ifconfig
eth0 Link encap:Ethernet HWaddr 00:60:67:44:A8:BF
inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2183 errors:0 dropped:0 overruns:0 frame:0
TX packets:2006 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
Interrupt:10 Base address:0xec00
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:3924 Metric:1
RX packets:203 errors:0 dropped:0 overruns:0 frame:0
TX packets:203 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
borealis:~# ssh jake@nothing -t ping -c 4 140.186.109.11
jake@nothing.megabite.net's password:
PING 140.186.109.11 (140.186.109.11): 56 data bytes
64 bytes from 140.186.109.11: icmp_seq=0 ttl=255 time=0.9 ms
64 bytes from 140.186.109.11: icmp_seq=1 ttl=255 time=0.2 ms
64 bytes from 140.186.109.11: icmp_seq=2 ttl=255 time=0.2 ms
64 bytes from 140.186.109.11: icmp_seq=3 ttl=255 time=0.2 ms
--- 140.186.109.11 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.2/0.3/0.9 ms
Connection to nothing.megabite.net closed.
borealis:~# ipchains -L
Chain input (policy ACCEPT):
Chain forward (policy ACCEPT):
Chain output (policy ACCEPT):
borealis:~#
that interface, although invisible, will remain available until a reboot. i
can even `ifdown eth0 ; ifup eth0` and not loose it. is this an expected
reaction?
--
(jacob kuntz) jpk@cape.com jake@{megabite,underworld}.net
(megabite systems) "...racing accross antarctica, towing steam
rollers through a mine field." (sgwaps)
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This archive was generated by hypermail 2b29 : Wed Jun 07 2000 - 21:00:26 EST