From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Routing issue in a strange configuration. Date: Mon, 16 Jun 2003 12:10:01 -0700 Sender: netdev-bounce@oss.sgi.com Message-ID: <3EEE1609.1020809@candelatech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: To: "'netdev@oss.sgi.com'" Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org I have a machine with eth1 IP 10.3.1.4 and eth2 with 10.3.2.4 I am using source-based routing, and have the eth1 & 2 ports connected to another machine which is acting as a route (the other machine has 10.3.1.1 and 10.3.2.1 IP addresses). I run ping with the -I option to bind it to eth1, but instead of sending the arp and/or ICMP request to the gateway, it instead arps for the IP on eth2. The machines are running RedHat 9, and the problem exists in the default 2.4.20-8 kernel. I have not tried other kernels yet, so if you think this is a RedHat only issue, I can try the stock kernel. Here is the output from the machine that is attempting to send the traffic: [root@localhost root]# ifconfig eth0 Link encap:Ethernet HWaddr 00:03:47:2B:39:CA inet addr:192.168.1.22 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1362 errors:0 dropped:0 overruns:0 frame:0 TX packets:1345 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:80208 (78.3 Kb) TX bytes:1705206 (1.6 Mb) Interrupt:11 Base address:0xdf00 Memory:feafe000-feafe038 eth1 Link encap:Ethernet HWaddr 00:03:47:2B:39:CB inet addr:10.3.1.4 Bcast:10.3.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:8 errors:0 dropped:0 overruns:0 frame:0 TX packets:377 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:400 RX bytes:596 (596.0 b) TX bytes:16338 (15.9 Kb) Interrupt:11 Base address:0xde80 Memory:feafd000-feafd038 eth2 Link encap:Ethernet HWaddr 00:50:C2:11:32:64 inet addr:10.3.2.4 Bcast:10.3.2.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:3 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) Interrupt:11 Base address:0xbc00 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:1418 errors:0 dropped:0 overruns:0 frame:0 TX packets:1418 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:1938073 (1.8 Mb) TX bytes:1938073 (1.8 Mb) [root@localhost root]# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 10.3.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 10.3.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth2 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 192.168.1.5 0.0.0.0 UG 0 0 0 eth0 [root@localhost root]# ip ru 0: from all lookup local 32758: from 10.3.2.4 lookup 2 32759: from 10.3.1.4 lookup 1 32766: from all lookup main 32767: from all lookup 253 [root@localhost root]# ip route show table 1 10.3.1.0/24 via 10.3.1.4 dev eth1 default via 10.3.1.1 dev eth1 [root@localhost root]# ip route show table 2 10.3.2.0/24 via 10.3.2.4 dev eth2 default via 10.3.2.1 dev eth2 [root@localhost root]# ping -I eth1 10.3.1.1 PING 10.3.1.1 (10.3.1.1) from 10.3.1.4 eth1: 56(84) bytes of data. 64 bytes from 10.3.1.1: icmp_seq=1 ttl=64 time=0.167 ms 64 bytes from 10.3.1.1: icmp_seq=2 ttl=64 time=0.087 ms # The other interface on the router machine (same machine as I just pinged above) [root@localhost root]# ping -I eth1 10.3.2.1 PING 10.3.2.1 (10.3.2.1) from 10.3.1.4 eth1: 56(84) bytes of data. From 10.3.1.4 icmp_seq=1 Destination Host Unreachable From 10.3.1.4 icmp_seq=3 Destination Host Unreachable # It is NOT using the default gateway for this traffic, but is instead # just trying to ARP. [root@localhost root]# tcpdump -n -i eth1 tcpdump: listening on eth1 11:56:19.788336 arp who-has 10.3.2.1 tell 10.3.1.4 11:56:20.788134 arp who-has 10.3.2.1 tell 10.3.1.4 11:56:21.788149 arp who-has 10.3.2.1 tell 10.3.1.4 11:56:22.788379 arp who-has 10.3.2.1 tell 10.3.1.4 -- Ben Greear President of Candela Technologies Inc http://www.candelatech.com ScryMUD: http://scry.wanfear.com http://scry.wanfear.com/~greear