From: W Walla (wallafly@hotmail.com)
Date: Wed Jul 21 2004 - 02:51:15 GMT-3
Thanks Dan. I will try that in the morning for sure.
But... IF I can telnet from Lan A to Lan B. And telnet Seperately From Lan B
to Lan C. But can not telnet directly from A right through Router B to Lan
C, will that MTU size be a possible issue?
I will try to clean the configs a bit so that I feel comfotable putting them
out there.
Thanks again - And to all that are reading this.
>From: "Daniel Sheedy" <dansheedy@gmx.net>
>Reply-To: "Daniel Sheedy" <dansheedy@gmx.net>
>To: "W Walla" <wallafly@hotmail.com>, <ccielab@groupstudy.com>
>Subject: Re: CAn Ping but not telnet /
>Date: Wed, 21 Jul 2004 07:40:32 +0200
>
>Hi Walla,
>
>here is the ping format:
>
>ping 192.168.3.1 -l 1500 -f
>
>: substitute the 192 address for something on the other lan.
>The -l is the packet load. Here it is 1500.
>The -f means 'i dont want you to fragment my packets'.
>
>So, it will try and send a packet from where you are, to the ip address in
>the ping command.
>
>If it is successfull, you will get a response. If not, it will say
>something like 'packet needs to be fragmented but DF bit is set'. Or it
>may
>give you a 'network unreachable' message if they have turned off/blocked
>ICMP messages.
>
>Your message may be a little different, as I cant remember the English
>message. Im working from a german OS at the moment. (fscking german...)
>
>Now, just keep decreasing the packet size until it gets through ok.
>Yesterday I had to keep getting smaller till it was 1378 for a DSL network.
>1378 goes through ok, but 1379 just disappears.
>
>Once you know what the smallest MTU from end to end is... then you can work
>on fixing it. Either getting your ISP to fix it, or you setting it on the
>routers.
>
>Also, router configs may help us out here. Maybe there is actually a
>config
>error.
>
>OK... have a go with that
>
>Dan Sheedy
>
>
>
>
>
>----- Original Message -----
>From: "W Walla" <wallafly@hotmail.com>
>To: <dansheedy@gmx.net>; <ccielab@groupstudy.com>
>Sent: Wednesday, July 21, 2004 7:26 AM
>Subject: Re: CAn Ping but not telnet /
>
>
> >
> > Hi, Thanks!
> > Interesting idea.
> >
> > I checked the configs on the routers just now and there is NO mention of
>MTU
> > anywhere.. Would you suggest that I set it, if so, to 1500? The link
>from
> > A to B routers is 256k, so maybe if I set the MTU it will send a larger
> > packet?
> >
> > When I am trying to telnet to a Server in LAN C, from LAN A (desktop) it
> > just times out...no refusal message. I can telnet From A to B though
>desktop
> > to a server.. And from LAn B to LAN C server to server... But again,
>not
> > A to C... SO strange to me!
> >
> > There is no PAT or anything like that, it is a Private Frame network and
>no
> > addressing shotage problems.
> > Does this give you a better idea?
> >
> > I can not get to the routers until the morning and my TAC acct has
> > expired... Getting a new smartnet soon.
> >
> > I will look up how to do the don't defrag bit and try that also in the
> > morning.
> > Thanks Dan!
> >
> > >From: "Daniel Sheedy" <dansheedy@gmx.net>
> > >To: "W Walla" <wallafly@hotmail.com>,<ccielab@groupstudy.com>
> > >Subject: Re: CAn Ping but not telnet /
> > >Date: Wed, 21 Jul 2004 07:11:03 +0200
> > >
> > >Hi Walla,
> > >
> > >Have you checked the MTU tfrom Lan A to Lan C? I had this problem from
> > >Australia to New Zealand once. Could do anything with tiny tiny
>packets,
> > >but as soon as it got bigger it timed out. It was a black hole in the
>ISP
> > >network combined with a smaller MTU.
> > >
> > >Do a ping from lan A to a computer on Lan C with the 'dont defragment'
>bit
> > >set.
> > >
> > >Also, what does it say, when you try to do a telnet? Does it just
>timeout?
> > >Or do you get a 'connection refused' message?
> > >Is there an access group under the line vty perchance?
> > >Is there NAT /PAT involved anywhere? Is so, is it passing through
> > >everything properly?
> > >
> > >Let us know what you find...
> > >
> > >Dan
> > >
> > >
> > >----- Original Message -----
> > >From: "W Walla" <wallafly@hotmail.com>
> > >To: <ccielab@groupstudy.com>
> > >Sent: Wednesday, July 21, 2004 7:00 AM
> > >Subject: CAn Ping but not telnet /
> > >
> > >
> > > > Not as easy as it sounds. I can ping across my wan from my lan
>through
> > >a
> > > > remote router and across that wan to another LAN. 0--0--0 A--B--C
><--
> > >like
> > > > this: From a through b to c's LAN. However! I can not telnet from
>A's
> > >LAN
> > > > into C's LAN.
> > > >
> > > > From A's LAN I can telnet and remote desktop into B's LAN.
> > > > From B's LAN I can Telnet and Remote desktop into C's LAN.
> > > > ButI can not Telnet or remote desktop from A's LAN into C's LAN
>through
> > > > Router B!
> > > >
> > > > I do not have any acl's applied on any routers... There used to be
>some
> > >but
> > > > they have been unapplied from any and all interfaces. I am not
>aware
>of
> > >any
> > > > Firewalls in between. WhenI trace router from Router A to Router C
>it
> > >hits
> > > > all appropriate interfaces along the way... Not like I could see a
> > >firewall
> > > > anyway probably..
> > > >
> > > > There is also some ospf and some statics on these routers...
> > > >
> > > > Anything jump out at anyone as the possible causes? I have
>reasearched
> > >this
> > > > for a full 2 days now and desperately need access.
> > > >
> > > > Help!
> > > >
> > > > Thanks!
> > > >
> > > > wallafly@hotmail.com
> > > >
> > > > _________________________________________________________________
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