[comp.dcom.sys.cisco] IBM RT's and Cisco

datk@is.morgan.com (Dave Atkinson) (05/26/91)

I have some IBM RT's that are running AIX 2.2.1 in Germany that don't want
to talk to our cisco router.  The RT's (like some RS6000's running AIX 3.1.5
that talk nicely with our cisco) are configured to use a default gateway.
I suspect something had been "tuned" on either the the cisco and/or RT's,	
because there were no problems before upgrading to 8.1.25.  There some 
evidence (still not confirmed) that cisco made some modifications/patch
to the 7.1 on our router to get it to speak with the RT's.
Cisco Technical Assistance says that the cisco should work with the RT's	
"right out of the box".  This does not seem to be the case -- at least with
these RT's.  All suggestions (aside from replacing the RT's with RS6000's	
- since that is what we plan to do anyway) are welcome.

hampton@cisco.com (David) (05/27/91)

Dave,

You don't mention whether this is ethernet or token ring.  Since it
is IBM, I will assume token ring.

Your problem sounds vaguely familiar.  We had a situation once where
an RT had a token ring chipset with an old TI bug.  The "bug" is that
it cannot handle packets where the first two bytes of the source
addresses are all zero.  Unfortunately, the first two bytes of cisco's
MAC address are zero.  Try changing the MAC address with the
"mac-address" command and see if this helps.

David


>> I have some IBM RT's that are running AIX 2.2.1 in Germany that don't want
>> to talk to our cisco router.  The RT's (like some RS6000's running AIX 3.1.5
>> that talk nicely with our cisco) are configured to use a default gateway.
>> I suspect something had been "tuned" on either the the cisco and/or RT's,	
>> because there were no problems before upgrading to 8.1.25.  There some 
>> evidence (still not confirmed) that cisco made some modifications/patch
>> to the 7.1 on our router to get it to speak with the RT's.
>> Cisco Technical Assistance says that the cisco should work with the RT's	
>> "right out of the box".  This does not seem to be the case -- at least with
>> these RT's.  All suggestions (aside from replacing the RT's with RS6000's	
>> - since that is what we plan to do anyway) are welcome.