Reviving an oldie but a goodie, based on some work I was doing today. I
wanted to check something that required 3 routers, and all I had were 2
routers and the 3550 switch. well, that's ok. L3 and all. BTW, have we
decided which is better - an L3 switch or a router? Hint - the L3 switch is
FAR
on the tunnel interface, works like a charm. Just thought it
was interesting so I figured I would send this.
~-Original Message-
~From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED]]
~Sent: Thursday, April 18, 2002 10:18 PM
~To: [EMAIL PROTECTED]
~Subject: Re: OSPF vs EIGRP [7:41613
At 10:57 PM -0400 4/18/02, nrf wrote:
Priscilla Oppenheimer wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
He didn't say that BGP negotiates the MTU in any of its PDUs. He just
says
that mismatched MTUs can be a problem, which is all I mentioned in my
message about OSPF also
There's not a word about MTU in draft 17 of the update to RFC1771
(even being on the working group, I'm not sure if draft 18 is out
yet). There is a maximum update length of 4K, but updates are
inherently variable length.
At 9:53 PM -0400 4/18/02, nrf wrote:
Really? I had never heard of
That's what I thought, which is why what suaveguru said made me so curious.
The only problems with MTU that I thought BGP would have are the same
problems that any IP packet might have with MTU (fragmentation, etc.)
Howard C. Berkowitz wrote in message
[EMAIL PROTECTED]">news:[EMAIL
BGP Keepalives are very short, but Updates can be very long. It looks like
they can be 4096 bytes from RFC 1771 (not counting headers).
BGP relies on TCP and IP, as you know, of course. Those layers would have
to make sure that the IP Don't Fragment bit was set to 0 (which means May
To:
Sent: Wednesday, April 17, 2002 8:32 PM
Subject: Re: OSPF and MTU, spawned from the OSPF vs. EIGRP thread [7:41788]
At 3:43 PM -0400 4/17/02, Kane, Christopher A. wrote:
In an attempt to find out why MTU is examined (more precisely, why it's
examined in the Database Description packets
If I am not wrong this problem also occurs for BGP
peers with unmatched MTU sizes which causes BGP to
flap when they exchange routing tables , especially if
one neighbour is configured with full-routes
regards,
suaveguru
--- Priscilla Oppenheimer wrote:
The problem happens when the routers
Really? I had never heard of this problem. I'm not aware that BGP
negotiates MTU in any of its PDU's. Can you provide the RFC that discusses
this problem?
suaveguru wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
If I am not wrong this problem also occurs for BGP
peers with
He didn't say that BGP negotiates the MTU in any of its PDUs. He just says
that mismatched MTUs can be a problem, which is all I mentioned in my
message about OSPF also (although OSPF does in fact also include the MTU in
database description packets and refuse to become adjacent with a router
Priscilla Oppenheimer wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
He didn't say that BGP negotiates the MTU in any of its PDUs. He just says
that mismatched MTUs can be a problem, which is all I mentioned in my
message about OSPF also (although OSPF does in fact also include
ATM Net that we
had). They would not form an adjacency, and the error message was about the
DDP packets, which could not be exchanged once that the MTU didn't match.
Persio
- Original Message -
From: Kane, Christopher A.
To:
Sent: Wednesday, April 17, 2002 12:33 PM
Subject: RE: OSPF vs
Kane, Christopher A. wrote in message
news:[EMAIL PROTECTED]...
The most frequently mismatched parameters relevant for OSPF
configuration
seem to be dead intervals mtu sizes.
OSPF doesn't care about MTU size.
Uh, excuse me? Go read RFC 2178 (OSPF v2), section G.9:
When two
The most frequently mismatched parameters relevant for OSPF
configuration
seem to be dead intervals mtu sizes.
OSPF doesn't care about MTU size.
Uh, excuse me? Go read RFC 2178 (OSPF v2), section G.9:
When two neighboring routers have a different interface MTU for their
In an attempt to find out why MTU is examined (more precisely, why it's
examined in the Database Description packets instead of the Hello packets)
one of my co-workers found this passage in IETF meeting minutes:
Editor's note: These minutes have not been edited.
The OSPF Working Group met on
You got here just before I did. I was just about to say that RFC 2328
overrides 2178.
Kane, Christopher A. wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
The most frequently mismatched parameters relevant for OSPF
configuration
seem to be dead intervals mtu sizes.
The problem happens when the routers try to exchange database description
packets. One side can send packets that are too large for the other side to
receive. Then the routers never achieve adjacency. It's an infamous
problem. I was glad that Kevin brought it up. I was thinking we should have
At 3:43 PM -0400 4/17/02, Kane, Christopher A. wrote:
In an attempt to find out why MTU is examined (more precisely, why it's
examined in the Database Description packets instead of the Hello packets)
one of my co-workers found this passage in IETF meeting minutes:
Editor's note: These minutes
What experiences have people had in setting up and maintaining OSPF vs EIGRP
on a large network?
I'm aware of the proprietary implications of EIGRP and the basic differences
in design of the protocols - how they are _supposed_ to work, but, in
practice, would you say one is more stable
-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
Madory Douglas C 1Lt 603 ACS/LGC
Sent: Tuesday, April 16, 2002 10:21 AM
To: [EMAIL PROTECTED]
Subject: OSPF vs EIGRP [7:41613]
What experiences have people had in setting up and maintaining OSPF vs EIGRP
on a large network?
I'm
Also, what about OSPF between Cisco and non-Cisco products?
Do they always
work together like they're supposed to?
Doug,
I've worked with OSPF in a multi-vendor environment and had no problems. All
the required parameters in the Hello packets were met and neigh/adj's were
established with
Hi folks,
Is there any sort of Cisco white paper out there which
provides a decision tree for determining whether to deploy OSPF versus
EIGRP.
Thanks in
advance,
Irwin
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