I have a load balanced outbound internet access setup on my SLES 11 SP1 server. This config wors perfectly fine on SLES 9 SP3. However in SLES11 SP1 while the load balancing works fine I have one small issue for dead gateway detection.

When all my VLAN interfaces are up, I am able to ping the internet ONLY using the VLAN interface that has the default route setup to go through it.

In detail: before the load balancing is setup my default route is through vlan4 and I am able to ping anything on the internet through VLAN4. However eventhough VLAN5 is up, any pings to internet thru VLAN5 fails. Once I change default route to use VLAN5 the problem is solved, But VLAN4 stops.

When my load balance script changes the default route to multi-path across all the VLAN interfaces, things are again fine.

But I need to be able to ping through a interface that does not have default route setup thru it to help detect dead gateways. Herein lies my problem. In SLES9 everything works. Is there some change in SLES11 SP1 that is causing this.

To explaing my NIC config: There are 4 nics (eth0 to 3). Three are bonded together (eth0 to 2). A bridge (br0) to the bonded iface connects my local network. Eth3 has four VLANS (VLAN4 to 7) connected to the net thru four independant ADSL router-modems. Each VLAN interface accesses one router-modem.

Output of IFOCNFIG is below. Output of ROUTE (before load balancing) follows this. Output of PING follows last.


================
bond0 Link encap:Ethernet HWaddr 00:14:38:B8:8E:8A
UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1
RX packets:42656 errors:0 dropped:0 overruns:0 frame:0
TX packets:16869 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:5997078 (5.7 Mb) TX bytes:11670363 (11.1 Mb)

br0 Link encap:Ethernet HWaddr 00:14:38:B8:8E:8A
inet addr:192.168.2.4 Bcast:192.168.2.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:41121 errors:0 dropped:0 overruns:0 frame:0
TX packets:15664 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:4765499 (4.5 Mb) TX bytes:11424153 (10.8 Mb)

eth0 Link encap:Ethernet HWaddr 00:14:38:B8:8E:8A
UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
RX packets:7963 errors:0 dropped:0 overruns:0 frame:0
TX packets:15932 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1095119 (1.0 Mb) TX bytes:11544892 (11.0 Mb)
Interrupt:48

eth1 Link encap:Ethernet HWaddr 00:14:38:B8:8E:8A
UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
RX packets:20251 errors:0 dropped:0 overruns:0 frame:0
TX packets:418 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2226292 (2.1 Mb) TX bytes:53108 (51.8 Kb)
Interrupt:76

eth2 Link encap:Ethernet HWaddr 00:14:38:B8:8E:8A
UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
RX packets:14442 errors:0 dropped:0 overruns:0 frame:0
TX packets:519 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2675667 (2.5 Mb) TX bytes:72363 (70.6 Kb)
Interrupt:26

eth3 Link encap:Ethernet HWaddr 00:12:79:3A:21:FC
inet addr:192.168.8.4 Bcast:192.168.8.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:428 errors:0 dropped:0 overruns:0 frame:0
TX packets:1044 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:87064 (85.0 Kb) TX bytes:75636 (73.8 Kb)
Interrupt:17

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:1323 errors:0 dropped:0 overruns:0 frame:0
TX packets:1323 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:134772 (131.6 Kb) TX bytes:134772 (131.6 Kb)

vlan4 Link encap:Ethernet HWaddr 00:12:79:3A:21:FC
inet addr:192.168.4.4 Bcast:192.168.4.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:274 errors:0 dropped:0 overruns:0 frame:0
TX packets:319 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:70452 (68.8 Kb) TX bytes:25328 (24.7 Kb)

vlan5 Link encap:Ethernet HWaddr 00:12:79:3A:21:FC
inet addr:192.168.5.4 Bcast:192.168.5.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:50 errors:0 dropped:0 overruns:0 frame:0
TX packets:247 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:2296 (2.2 Kb) TX bytes:10414 (10.1 Kb)

vlan6 Link encap:Ethernet HWaddr 00:12:79:3A:21:FC
inet addr:192.168.6.4 Bcast:192.168.6.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:54 errors:0 dropped:0 overruns:0 frame:0
TX packets:238 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:2604 (2.5 Kb) TX bytes:10036 (9.8 Kb)

vlan7 Link encap:Ethernet HWaddr 00:12:79:3A:21:FC
inet addr:192.168.7.4 Bcast:192.168.7.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:50 errors:0 dropped:0 overruns:0 frame:0
TX packets:238 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:2296 (2.2 Kb) TX bytes:10036 (9.8 Kb)
=================================

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.7.0 * 255.255.255.0 U 0 0 0 vlan7
192.168.6.0 * 255.255.255.0 U 0 0 0 vlan6
192.168.5.0 * 255.255.255.0 U 0 0 0 vlan5
192.168.4.0 * 255.255.255.0 U 0 0 0 vlan4
192.168.2.0 * 255.255.255.0 U 0 0 0 br0
192.168.8.0 * 255.255.255.0 U 0 0 0 eth3
link-local * 255.255.0.0 U 0 0 0 eth3
loopback * 255.0.0.0 U 0 0 0 lo
default airtel-cli-rtr 0.0.0.0 UG 0 0 0 vlan4
========================================


ping -c1 -I vlan4 gmail.com
PING gmail.com (74.125.236.54) from 192.168.4.4 vlan4: 56(84) bytes of data.
64 bytes from maa03s04-in-f22.1e100.net (74.125.236.54): icmp_seq=1 ttl=56 time=31.3 ms

--- gmail.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 31.361/31.361/31.361/0.000 ms


Please help.


Ramesh.