Bill: This has nothing to do with MTU size. MTU size determines the maximum size of a datagram. The datagrams are packed into a 32K buffer for transport across the CTCA. That's where the problem is occurring.
Romney On Wed, 13 Feb 2002 11:49:03 -0500 Scully, William said: >Thanks for the info Romney! On one of the Linux servers where I get the >error, I did an IFCONFIG and I find: > > >linux017:~ # ifconfig >ctc0 Link encap:Serial Line IP > inet addr:141.202.232.131 P-t-P:141.202.198.101 >Mask:255.255.255.255 > UP POINTOPOINT RUNNING NOARP MTU:1500 Metric:1 > RX packets:7407345 errors:0 dropped:0 overruns:0 frame:0 > TX packets:13113625 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:100 > >lo Link encap:Local Loopback > inet addr:127.0.0.1 Mask:255.0.0.0 > UP LOOPBACK RUNNING MTU:3924 Metric:1 > RX packets:2629004 errors:0 dropped:0 overruns:0 frame:0 > TX packets:2629004 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > > >I see an MTU of 1500 on ctc0. So how did such a large packet end up on the >CTC between Linux and VM? > >-----Original Message----- >From: Romney White [mailto:[EMAIL PROTECTED]] >Sent: Wednesday, February 13, 2002 11:02 AM >To: [EMAIL PROTECTED] >Subject: Re: TCP/IP and Linux > > >Bill: > >The message is documenting the fact that Linux sent a malformed block >of packets across the CTCA. The blocks may be up to 32K (32768 bytes) >long, so a packet starting at 33134 is clearly an error. The offending >packet is at offset 31628 in the buffer. > >I presume that there is a mismatch in the buffer size between Linux >and VM TCP/IP and hope there is a control you can set on the Linux >side to use a buffer size of 32K. > >Romney > >On Wed, 13 Feb 2002 10:55:27 -0500 Scully, William said: >>(Cross-posted to the VM and Linux on 390 lists) >> >>We find a lot of the following messages on TCP/IP's console (FL 3A0) >>regarding the CTCs for Linux servers: >> >>22:50:10 DTCCTC008E CTCA device LINUX016: UnpackReads: Inv blk hdr 33134 >>from input position 31628. Last blk hdr 0. Discarding remainder of block. >> >> >>Are others of you out there seeing this? The message doesn't seem to be >>documented. What does it mean? It appears that some (but not all) servers >>loose connectivity when this happens. >> >>William P. Scully >>Systems Programmer >>Computer Associates International, Inc >>[EMAIL PROTECTED]
