From: Barney Gaumer (bagaumer@yahoo.com)
Date: Mon Aug 18 2003 - 13:39:45 GMT-3
Scott,
He could have also used the mtu-ignore command on the
3550's interface to eliminate the DBD retrans. I've
used this successfully to interop with a Nokia FW team
that had a larger MTU. Instead of messing with the
MTU size on the Cisco gear I just told it to ingore
the MTU size of the Noks and poof! it worked.
But as always - there's more than one way to skin a
cat :)
Barney
--- Scott Morris <swm@emanon.com> wrote:
> Now, now, be nice... If he changed his MTU, then
> absolutely it's an
> issue... Default operation though even accepting
> frame sizes to 1518
> (as I noted) does not make the MTU 1518...
>
> So... If you don't mess with the MTU, there is no
> issue working with a
> 3550. If you mess with the MTU on ANY device, then
> there will be an
> issue trying to get things to work right!
>
> Out of the box, by default though, the MTU is not
> 1518. (Caveat (since
> I want to avoid correction): On any of the numerous
> 3550's I've seen)
> If you have purchased a used one, perhaps things are
> different. *shrug*
>
> But judging by reading the original message about "I
> created vlan 10",
> then things should be "normal". And I believe I
> also note "If you did,
> that's what's messed up. If you didn't, look at the
> bug id referenced
> above. Try a different IOS."
>
> :)
>
> Scott
>
>
>
> -----Original Message-----
> From: John Matijevic [mailto:matijevi@bellsouth.net]
>
> Sent: Monday, August 18, 2003 9:34 AM
> To: Seonghui; Scott Morris; 'Mustafa M Bayramov';
> ccielab@groupstudy.com
> Subject: Re: cat3550 cannot establish ospf nei with
> router/s
>
>
> Hello Seong,
> I am glad it is working for you now. It looks like
> it was an mtu issue
> all along as I had first mentioned. Scott Morris had
> mentioned the
> following: It's not an MTU issue at all... Check
> out the IOS release
> you have. Bug CSCdv61151 mentions this. I want to
> correct Scott in that
> this was a MTU issue. Even a quadruple CCIE can be
> wrong sometimes.
> :)
> Sincerely,
> Matijevic
> ----- Original Message -----
> From: "Seonghui" <Seonghui@vads.com>
> To: "Scott Morris" <swm@emanon.com>; "'Mustafa M
> Bayramov'"
> <spyroot@azeronline.com>; <ccielab@groupstudy.com>
> Sent: Monday, August 18, 2003 5:22 AM
> Subject: RE: cat3550 cannot establish ospf nei with
> router/s
>
>
> > Yup, I got it working after deleting vlan.dat file
> and reloaded,
> > followed
> by
> > set system mtu 1500 and another reload for it to
> take effect. OSPF
> > works fine after that.
> >
> > But does every new switch comes with MTU 1518? I
> received 2 cat 35500
> > at
> the
> > same time, one by default is 1518 and the other
> one is 1500. Does it
> > mean that we have to check the MTU size on a
> switch before enabling L3
>
> > routing protocols in the exam?
> >
> > part of troubleshooting huh :)
> >
> > Thank you all for your help.
> >
> > -----Original Message-----
> > From: Scott Morris [mailto:swm@emanon.com]
> > Sent: Monday, August 18, 2003 5:10 AM
> > To: 'Mustafa M Bayramov'; 'seonghui';
> ccielab@groupstudy.com
> > Subject: RE: cat3550 cannot establish ospf nei
> with router/s
> >
> >
> > I would agree... Before an RMA, do a 'write
> erase' and 'del vlan.dat'
>
> > then reload the sucker and see what happens.
> >
> > Karma? :)
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com] On Behalf
> > Of Mustafa M Bayramov
> > Sent: Sunday, August 17, 2003 1:13 PM
> > To: 'seonghui'; 'Scott Morris';
> ccielab@groupstudy.com
> > Subject: RE: cat3550 cannot establish ospf nei
> with router/s
> >
> >
> > Make delete vlan.dat and you will see switch will
> set default MTU 1518
> >
> > To fix this you can change system MTU ( need
> restart switch ) Adjust
> > MTU per VLAN. Adjust MTU for SWI interface. Set ip
> ospf mtu-ignore for
>
> > ospf on both routers.
> >
> > Regards
> >
> >
> > Mustafa M Bayramov
> >
> > CISSP
> > CCNP,CCDP,Cisco Security Specialist
> > Network engineer and security analyst
> >
> > Azercell Telecom J.V.
> >
> > "I know nothing except the fact of my ignorance."
> Socrates
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com] On Behalf
> > Of seonghui
> > Sent: Saturday, August 16, 2003 11:20 PM
> > To: 'Scott Morris'; ccielab@groupstudy.com
> > Subject: RE: cat3550 cannot establish ospf nei
> with router/s
> >
> > Hi Scott,
> >
> > OK, this sounds reasonable. But I have tried the
> same setting and
> > config. on another identical cat3550 switch,
> running the same IOS code
> >
>
(flash:c3550-i5q3l2-mz.121-13.EA1a/c3550-i5q3l2-mz.121-13.EA1a.bin)
>
> > and it works! OSPF nei adj formed almost instantly
> with the
> > router...this puzzles me. can i just send the
> switch for RMA?
> >
> > anyway, thanks group for your help. I better leave
> this problem alone,
>
> > else i'll be wasting too much time and never move
> on.
> >
> > regards-SH
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com]On Behalf Of
>
> > Scott Morris
> > Sent: Sunday, August 17, 2003 3:04 AM
> > To: 'John Matijevic'; 'MMoniz'; 'seonghui';
> ccielab@groupstudy.com
> > Subject: RE: cat3550 cannot establish ospf nei
> with router/s
> >
> >
> > It's not an MTU issue at all... Check out the IOS
> release you have.
> > Bug CSCdv61151 mentions this.
> >
> > I just set it up on a 3550 and three different
> routers (2610 and two
> > different 3620's) and ospf came up immediately.
> No MTU playing,
> > nothing funky, nothing bizarre, just simple
> network command and *POOF*
>
> > there were neighbors and routes and reachability!
> >
> > The switch is wholly aware of different things
> because it's a switch.
> > :) Looking at show interface, the MTU should be
> 1500 on everything.
>
=== message truncated ===
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This archive was generated by hypermail 2.1.4 : Tue Sep 02 2003 - 18:54:01 GMT-3