From: Richard Dumoulin (richard.dumoulin@vanco.es)
Date: Fri Apr 23 2004 - 17:12:17 GMT-3
By the way LAM (Local Area Mobility) is based on host routes. The issue is
that I believe it is Cisco proprietary ?
-----Original Message-----
From: Richard Dumoulin
Sent: viernes, 23 de abril de 2004 22:06
To: 'BALAKRISHNAN Balaji'; Kenneth Wygand; ccielab@groupstudy.com
Subject: RE: RFC 1812 " Requirements for IP Version 4 Routers" ??
Bala, the documents tell how the protocols should work and what Kenneth did
is show how it they actually work !
I would just show your manager a real scenario and if he still does not
believe it then ... he has a problem (just kidding),
--Richard
-----Original Message-----
From: BALAKRISHNAN Balaji [mailto:Balaji.BALAKRISHNAN@swift.com]
Sent: viernes, 23 de abril de 2004 21:39
To: Kenneth Wygand; ccielab@groupstudy.com
Subject: RE: RFC 1812 " Requirements for IP Version 4 Routers" ??
Yes.I knew. That's what I said in the original email. But I am looking for
RFC document reference which clearly indicates this. My manager will be more
happy to see in document rathan than in lab :::)))
- Bala.
>-----Original Message-----
>From: Kenneth Wygand [mailto:KWygand@customonline.com]
>Sent: Friday, April 23, 2004 2:49 PM
>To: BALAKRISHNAN Balaji; ccielab@groupstudy.com
>Subject: RE: RFC 1812 " Requirements for IP Version 4 Routers" ??
>
>It will send the packet out based on the longest match in the routing
>table, regardless of whether or not the router knows about it as a
>directly connected interface. See below output capture.
>
><snip>
>Lab_A#conf t
>Enter configuration commands, one per line. End with CNTL/Z.
>Lab_A(config)#exit Lab_A#sh ip int brie
>04:11:36: %SYS-5-CONFIG_I: Configured from console by consolef
>Interface IP-Address OK? Method Status
>Protocol
>Ethernet0 192.168.0.1 YES manual up
>up
>Serial0 201.101.0.1 YES manual up
>up
>Serial1 200.100.0.1 YES manual administratively down
>down
>Lab_A#debug ip packet
>IP packet debugging is on
>Lab_A#
>Lab_A#
>Lab_A#
>Lab_A#ping 192.168.0.10
>
>Type escape sequence to abort.
>Sending 5, 100-byte ICMP Echos to 192.168.0.10, timeout is 2 seconds:
>
>04:11:47: IP: s=192.168.0.1 (local), d=192.168.0.10 (Ethernet0), len
>100, sendin g
>04:11:47: IP: s=192.168.0.1 (local), d=192.168.0.10 (Ethernet0), len
>100, encaps
>ulation failed.
>04:11:49: IP: s=192.168.0.1 (local), d=192.168.0.10 (Ethernet0), len
>100, sendin
>g
>04:11:49: IP: s=192.168.0.1 (local), d=192.168.0.10 (Ethernet0), len
>100, encaps
>ulation failed.
>04:11:51: IP: s=192.168.0.1 (local), d=192.168.0.10 (Ethernet0), len
>100, sendin
>g
>04:11:51: IP: s=192.168.0.1 (local), d=192.168.0.10 (Ethernet0), len
>100, encaps
>ulation failed.
>04:11:53: IP: s=192.168.0.1 (local), d=192.168.0.10 (Ethernet0), len
>100, sendin
>g
>04:11:53: IP: s=192.168.0.1 (local), d=192.168.0.10 (Ethernet0), len
>100, encaps
>ulation failed.
>04:11:55: IP: s=192.168.0.1 (local), d=192.168.0.10 (Ethernet0), len
>100, sendin
>g
>04:11:55: IP: s=192.168.0.1 (local), d=192.168.0.10 (Ethernet0), len
>100, encaps
>ulation failed.
>Success rate is 0 percent (0/5)
>Lab_A#
>Lab_A#
>Lab_A#conf t
>Enter configuration commands, one per line. End with CNTL/Z.
>Lab_A(config)#ip route 192.168.0.10 255.255.255.255 ser0
>Lab_A(config)#exit
>Lab_A#ping 192.168.0.10
>04:12:15: %SYS-5-CONFIG_I: Configured from console by console
>
>Type escape sequence to abort.
>Sending 5, 100-byte ICMP Echos to 192.168.0.10, timeout is 2 seconds:
>
>04:12:18: IP: s=201.101.0.1 (local), d=192.168.0.10 (Serial0), len 100,
>sending.
>04:12:20: IP: s=201.101.0.1 (local), d=192.168.0.10 (Serial0), len 100,
>sending.
>04:12:22: IP: s=201.101.0.1 (local), d=192.168.0.10 (Serial0), len 100,
>sending.
>04:12:24: IP: s=201.101.0.1 (local), d=192.168.0.10 (Serial0), len 100,
>sending.
>04:12:26: IP: s=201.101.0.1 (local), d=192.168.0.10 (Serial0), len 100,
>sending. Success rate is 0 percent (0/5)
>Lab_A#
></snip>
>
>Kenneth E. Wygand
>Systems Engineer, Project Services
>CISSP #37102, CCNP, CCDP, ACSP, Cisco IPT Design Specialist, MCP, CNA,
>Network+, A+
>Custom Computer Specialists, Inc.
>"The only unattainable goal is the one not attempted." -Anonymous
>
>-----Original Message-----
>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
>BALAKRISHNAN Balaji
>Sent: Friday, April 23, 2004 2:30 PM
>To: ccielab@groupstudy.com
>Subject: RFC 1812 " Requirements for IP Version 4 Routers" ??
>
>Hi group,
>
>I have a clarification on RFC1812 about route forwarding decision..
>
>When a router received a packet, if the destination ip is part of its
>directly connected interface subnet , it will do the arp request for
>that destination ip out to that interface. Now, we can change that
>behavior by configuring more specific route for that destination ( say
>/32 host route) pointing to different gateway. On this case, router
>forwards the packet to the next-hop defined. right ???
>
>But my manager don't agree with that. He says if destination IP
>address in the packet is on the same subnet as any Ethernet interface
>of the router, then the router should not do any route lookup at all,
>and must immediately forward the packet on that matching interface .
>Ie. more specific route present in the router's routing table is then
>not relevant. He pointing to the RFC 1812 section "5.2.4.2
>Local/Remote decision ". The section goes line this ..the following
>algorithm MUST be
>used to determine if the Immediate Destination is directly accessible
>quote
> * isolate the network prefix used by the interface.
> * Isolate the corresponding set of bits from the IP Destination
>Address of the packet.
> * Compare the resulting network prefixes. If they are
>equal to each
>other, the packet can be transmitted through the corresponding network
> interface.
> * If the destination was not a member of a directly
>connected network
>prefix, the IP Destination is accessible only through some other
> router.
>unquote
>
>I believe it does not consider all the possibilities for a route
>decision. Do anybody know better RFC reference that I can point to my
>manager to prove that I am right ???
>
>- bala.
>
>_______________________________________________________________________
>Please help support GroupStudy by purchasing your study materials from:
>http://shop.groupstudy.com
>
>Subscription information may be found at:
>http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Mon May 03 2004 - 19:48:54 GMT-3