Messages in this thread | | | Date | Thu, 5 Jan 2006 10:20:54 +0100 | From | JohnnyRun <> | Subject | eth0 and loopback problems. |
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Hi all! I think it's a bug....
HOSTA# ifconfig eth0 192.168.0.1 HOSTA# ifconfig eth0 down HOSTA# ping 192.168.0.1 (the ping works, like all other ICMP / TCP /UDP ... application. In other words: all work like eth0 in UP mode when source and destination point comunicate via loopback device. I think it's not correct because if eth0 is DOWN for all the hosts in LAN should be down for me too. Or not?
Suppose another conf:
HOSTA# ifconfig eth0 Link encap:Ethernet HWaddr 00:10:DC:C3:5E:FF inet addr:192.168.0.1 Bcast:192.168.0.255 Mask:255.0.0.0 BROADCAST MULTICAST MTU:1500 Metric:1 eth1 Link encap:Ethernet HWaddr 00:0E:35:74:16:67 inet addr:192.168.0.2 [...] UP BROADCAST RUNNING MULTICAST MTU:1500 lo [...]
HOSTB# ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:00:24:C8:4A:7D inet addr:192.168.0.1 Bcast:1.255.255.255 Mask:255.0.0.0 UP BROADCAST RUNNING MULTICAST MTU:1500 [...]
So, HOSTA and HOSTB share the same ip but: HOSTA eth0 is DOWN; HOSTA eth1 is UP, HOSTB eth0 is UP. So, no conflict should be possible. but:
HOSTB# ping 192.168.0.2 (does not reply)
So I suppose that HOSTA route the icmp reply through its lo. But:
HOSTA# tcpdump -i lo doesn't show any reply, and
HOSTA# tcpdump -i eth0 it's not permitted, because eth0 is DOWN.
The same result for TCP protocol (tested with hping). Operative conditions: Linux 2.6.14, HOSTA eth1 is wifi. Regards JohnnyRun - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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