Hello there, I'm facing the following issue : when I try to ping using source interface instead of a source ip address the ping utility starts to send arp requests instead of icmp requests though the ip address I'm pinging it's not in the subnets directly connected to my linux box. I've noticed this situation since I upgraded from kernel 2.6.20 to 2.6.21. On 2.6.20 and lower I haven't had this problem. Now I upgraded to 2.6.22 but it's the same. I'm using latest iproute and iputils. Here is an output of tcpdump when I try to ping an outside ip address, like for example www.yahoo.com, using source interface :
[EMAIL PROTECTED]:~# uname -a Linux darkstar 2.6.22 #1 Thu Jul 26 21:22:11 EEST 2007 i686 Pentium II (Deschutes) GenuineIntel GNU/Linux [EMAIL PROTECTED]:~# ip -V ip utility, iproute2-ss070710 [EMAIL PROTECTED]:~# [EMAIL PROTECTED]:~# ip address show dev eth2 3: eth2: <BROADCAST,MULTICAST,NOTRAILERS,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:90:27:0f:79:f3 brd ff:ff:ff:ff:ff:ff inet 86.106.19.75/23 brd 86.106.19.255 scope global eth2 [EMAIL PROTECTED]:~# ip route get 87.248.113.14 from 86.106.19.75 oif eth2 87.248.113.14 from 86.106.19.75 via 86.106.18.1 dev eth2 cache mtu 1500 advmss 1460 hoplimit 64 [EMAIL PROTECTED]:~# [EMAIL PROTECTED]:~/iputils# ./ping -V ping utility, iputils-sss20070202 [EMAIL PROTECTED]:~/iputils# ./ping -I 86.106.19.75 87.248.113.14 -c 2 PING 87.248.113.14 (87.248.113.14) from 86.106.19.75 : 56(84) bytes of data. 64 bytes from 87.248.113.14: icmp_seq=1 ttl=51 time=60.5 ms 64 bytes from 87.248.113.14: icmp_seq=2 ttl=51 time=63.2 ms --- 87.248.113.14 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 999ms rtt min/avg/max/mdev = 60.574/61.924/63.274/1.350 ms [EMAIL PROTECTED]:~/iputils# [EMAIL PROTECTED]:~# tcpdump -i eth2 -vvv -n host 87.248.113.14 and host 86.106.19.75 tcpdump: listening on eth2, link-type EN10MB (Ethernet), capture size 96 bytes 01:18:09.572603 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto: ICMP (1), length: 84) 86.106.19.75 > 87.248.113.14: ICMP echo request, id 27166, seq 1, length 64 01:18:09.632861 IP (tos 0x0, ttl 51, id 6100, offset 0, flags [none], proto: ICMP (1), length: 84) 87.248.113.14 > 86.106.19.75: ICMP echo reply, id 27166, seq 1, length 64 01:18:10.572746 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto: ICMP (1), length: 84) 86.106.19.75 > 87.248.113.14: ICMP echo request, id 27166, seq 2, length 64 01:18:10.634951 IP (tos 0x0, ttl 51, id 8790, offset 0, flags [none], proto: ICMP (1), length: 84) 87.248.113.14 > 86.106.19.75: ICMP echo reply, id 27166, seq 2, length 64 using source interface : [EMAIL PROTECTED]:~/iputils# ./ping -I eth2 87.248.113.14 PING 87.248.113.14 (87.248.113.14) from 86.106.19.75 eth2: 56(84) bytes of data. >From 86.106.19.75 icmp_seq=1 Destination Host Unreachable >From 86.106.19.75 icmp_seq=2 Destination Host Unreachable >From 86.106.19.75 icmp_seq=3 Destination Host Unreachable >From 86.106.19.75 icmp_seq=5 Destination Host Unreachable >From 86.106.19.75 icmp_seq=6 Destination Host Unreachable >From 86.106.19.75 icmp_seq=7 Destination Host Unreachable >From 86.106.19.75 icmp_seq=9 Destination Host Unreachable >From 86.106.19.75 icmp_seq=10 Destination Host Unreachable >From 86.106.19.75 icmp_seq=11 Destination Host Unreachable --- 87.248.113.14 ping statistics --- 13 packets transmitted, 0 received, +9 errors, 100% packet loss, time 12006ms , pipe 3 [EMAIL PROTECTED]:~/iputils# [EMAIL PROTECTED]:~# tcpdump -i eth2 -vvv -n host 87.248.113.14 and host 86.106.19.75 tcpdump: listening on eth2, link-type EN10MB (Ethernet), capture size 96 bytes 01:19:24.292911 arp who-has 87.248.113.14 tell 86.106.19.75 01:19:25.292897 arp who-has 87.248.113.14 tell 86.106.19.75 01:19:26.292901 arp who-has 87.248.113.14 tell 86.106.19.75 01:19:27.302906 arp who-has 87.248.113.14 tell 86.106.19.75 01:19:28.302911 arp who-has 87.248.113.14 tell 86.106.19.75 01:19:29.302912 arp who-has 87.248.113.14 tell 86.106.19.75 01:19:31.302917 arp who-has 87.248.113.14 tell 86.106.19.75 01:19:32.302921 arp who-has 87.248.113.14 tell 86.106.19.75 01:19:33.302923 arp who-has 87.248.113.14 tell 86.106.19.75 01:19:35.302932 arp who-has 87.248.113.14 tell 86.106.19.75 01:19:36.302932 arp who-has 87.248.113.14 tell 86.106.19.75 01:19:37.302939 arp who-has 87.248.113.14 tell 86.106.19.75 12 packets captured 12 packets received by filter 0 packets dropped by kernel [EMAIL PROTECTED]:~# There is one exception though, it works when using eth0. I'm administrating multiple linux boxes with 2 or 3 ethernet cards and if I try pinging with eth0 it does send icmp like it should but when specifying eth1 or eth2 is sends arp requests. The distro I'm using is Slackware 12.0. I already reported this to the iputils maintainer and he recommended to report it here. Thanks in advance. Regards. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
