Hi Jim, that was suppose to be OMPROUTE OSPF configuration file. I just verified that we use an MTU of 8992 on z/OS both in the OSPF file and the TCPIP file definitions. Obviously we are using Jumbo frames within our subnets.
It was a very long time ago that we set up our OSPF networks, and I seem to remember that using MTUs that were very small (like 1400) caused problems. I do believe we had it working with MTUs of 1492/1500 but later moved to jumbo frames as we used a Gigabit switch. Mark ----- Start Original Message ----- Sent: Tue, 22 Aug 2006 10:26:04 +0200 From: Mark Perry <[EMAIL PROTECTED]> To: Linux on 390 Port <[email protected]> Subject: Re: zLinux VIPA setup. > Hi Jim, > one other point, on z/OS you define the MTU in the MPROUTE OSPF > configuration file, have you checked that? > > Regards > Mark > > Mark Perry wrote: > > Hi Jim, > > Well MTU is the problem. The HELLO packets are short and hence why you > > "know" you have neighbours, but any further packets will be much > > larger and that is why OSPF is not working. > > Do you have jumbo frames defined somewhere? > > What do "ip addr show" and "ip link show" produce? > > > > Something sticks in my mind about previously having problems with z/OS > > and z/Linux, I know we increased our MTUs (8192) and hence avoided the > > problem you are seeing. It may be that the MTU we used on z/OS was not > > exact, perhaps there is some header added on. Would need to research > > that and don't have time right now. > > > > To avoid many other problems we also turned on Path MTU Discovery on > > all systems. So perhaps we avoided this OSPF issue too? > > > > Sorry for being vague, but don't have the time to validate/reproduce > > your problem right now. > > > > Mark > > > > James K Barnett wrote: > >> Here is the quagga.log, Thanks for looking at it. > >> > >> I can't understand why I'm getting the MTU errors. All other MTUs > >> that > >> I could check are set at 1400, as is linux. > >> for reference. 185 is the vipa interface, the 51s are the eth > >> interfaces connected through vswitches to OSA cards. > >> > >> linux-00:/var/log/quagga # cat quagga.log > >> 2006/08/21 08:39:21 OSPF: interface 10.115.20.185 join AllSPFRouters > >> Multicast group. > >> 2006/08/21 08:39:21 OSPF: interface 10.115.136.51 join AllSPFRouters > >> Multicast group. > >> 2006/08/21 08:39:21 OSPF: interface 10.115.137.51 join AllSPFRouters > >> Multicast group. > >> 2006/08/21 08:39:22 OSPF: Packet[DD]: MTU is larger than > >> [eth0:10.115.136.51]'s MTU > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: Backup 10.115.136.31 > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: DR 10.115.136.31 > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: Backup 0.0.0.0 > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: DR 0.0.0.0 > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: Backup 0.0.0.0 > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: DR 0.0.0.0 > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: Backup 10.115.136.30 > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: DR 10.115.136.30 > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: Backup 0.0.0.0 > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: DR 0.0.0.0 > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: Backup 0.0.0.0 > >> 2006/08/21 08:39:23 OSPF: DR-Election[1st]: DR 0.0.0.0 > >> 2006/08/21 08:39:27 OSPF: Packet[DD]: MTU is larger than > >> [eth0:10.115.136.51]'s MTU > >> 2006/08/21 08:39:30 OSPF: DR-Election[1st]: Backup 10.115.137.1 > >> 2006/08/21 08:39:30 OSPF: DR-Election[1st]: DR 10.115.137.1 > >> 2006/08/21 08:39:30 OSPF: DR-Election[1st]: Backup 0.0.0.0 > >> 2006/08/21 08:39:30 OSPF: DR-Election[1st]: DR 10.115.137.1 > >> 2006/08/21 08:39:30 OSPF: Packet[DD]: MTU is larger than > >> [eth1:10.115.137.51]'s MTU > >> 2006/08/21 08:39:31 OSPF: DR-Election[1st]: Backup 0.0.0.0 > >> 2006/08/21 08:39:31 OSPF: DR-Election[1st]: DR 10.115.136.1 > >> 2006/08/21 08:39:32 OSPF: Packet[DD]: MTU is larger than > >> [eth0:10.115.136.51]'s MTU > >> 2006/08/21 08:39:33 OSPF: DR-Election[1st]: Backup 0.0.0.0 > >> 2006/08/21 08:39:33 OSPF: DR-Election[1st]: DR 10.115.137.1 > >> 2006/08/21 08:39:33 OSPF: DR-Election[1st]: Backup 0.0.0.0 > >> 2006/08/21 08:39:33 OSPF: DR-Election[1st]: DR 10.115.137.1 > >> 2006/08/21 08:39:35 OSPF: Packet[DD]: MTU is larger than > >> [eth1:10.115.137.51]'s MTU > >> 2006/08/21 08:39:37 OSPF: Packet[DD]: MTU is larger than > >> [eth0:10.115.136.51]'s MTU > >> 2006/08/21 08:39:40 OSPF: Packet[DD]: MTU is larger than > >> [eth1:10.115.137.51]'s MTU > >> 2006/08/21 08:39:42 OSPF: Packet[DD]: MTU is larger than > >> [eth0:10.115.136.51]'s MTU > >> 2006/08/21 08:39:45 OSPF: Packet[DD]: MTU is larger than > >> [eth1:10.115.137.51]'s MTU > >> 2006/08/21 08:39:47 OSPF: Packet[DD]: MTU is larger than > >> [eth0:10.115.136.51]'s MTU > >> 2006/08/21 08:39:50 OSPF: Packet[DD]: MTU is larger than > >> [eth1:10.115.137.51]'s MTU > >> 2006/08/21 08:39:52 OSPF: Packet[DD]: MTU is larger than > >> [eth0:10.115.136.51]'s MTU > >> 2006/08/2 > > > > > > ----- End Original Message ----- ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
