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)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/