From: Arun Arumuganainar (aarumuga@hotmail.com)
Date: Tue May 16 2006 - 12:36:42 ART
What version you were using ????
Actually I tried simulating this in my lab and I got the following result
Though the conclusion is that this is an invalid configuration . But the
behavior is slightly different .
Pls. Note : Static Route does gets installed . But ping is going through .
R2# conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#ip route 172.16.25.5 255.255.255.255 172.16.25.5
R2(config)#do sh ip route | in 172.16.25.
C 172.16.25.32/27 is directly connected, Ethernet0/0
S 172.16.25.5/32 [1/0] via 172.16.25.5
C 172.16.25.0/27 is directly connected, Serial1/1
R2(config)#do ping 172.16.25.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.25.5, timeout is 2 seconds:
....
Success rate is 0 percent (0/5)
R2(config)#no ip route 172.16.25.5 255.255.255.255 172.16.25.5
R2(config)#do ping 172.16.25.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.25.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/21/28 ms
R2(config)# ip route 172.16.25.5 255.255.255.255 172.16.25.5
R2(config)#do ping 172.16.25.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.25.5, timeout is 2 seconds:
....
Success rate is 0 percent (0/5)
R2(config)#no ip route 172.16.25.5 255.255.255.255 172.16.25.5
R2(config)#do ping 172.16.25.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.25.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/19/20 ms
R2(config)#
----- Original Message -----
From: "Brian McGahan" <bmcgahan@internetworkexpert.com>
To: "Arun Arumuganainar" <aarumuga@hotmail.com>; "D R"
<deep.ratan@gmail.com>; "Mark Lasarko" <mlasarko@co.ba.md.us>
Cc: <ccielab@groupstudy.com>
Sent: Tuesday, May 16, 2006 8:47 PM
Subject: RE: ip route to itself - rephrased
Connected as in assigned on the router itself I meant:
Rack1R1#show ip int brief | ex unassigned
Interface IP-Address OK? Method Status
Protocol
FastEthernet0/0 1.2.3.4 YES manual up up
Serial0/0 5.6.7.8 YES manual up up
Rack1R1#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS
inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
1.0.0.0/24 is subnetted, 1 subnets
C 1.2.3.0 is directly connected, FastEthernet0/0
5.0.0.0/24 is subnetted, 1 subnets
C 5.6.7.0 is directly connected, Serial0/0
Rack1R1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Rack1R1(config)#ip route 1.2.3.4 255.255.255.255 serial0/0
Rack1R1(config)#end
Rack1R1#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS
inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
1.0.0.0/24 is subnetted, 1 subnets
C 1.2.3.0 is directly connected, FastEthernet0/0
5.0.0.0/24 is subnetted, 1 subnets
C 5.6.7.0 is directly connected, Serial0/0
Rack1R1#
You can't override a connected address with routing regardless
of how specific the match is.
HTH,
Brian McGahan, CCIE #8593
bmcgahan@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987 x 705
Outside US: 775-826-4344 x 705
24/7 Support: http://forum.internetworkexpert.com
Live Chat: http://www.internetworkexpert.com/chat/
> -----Original Message-----
> From: Arun Arumuganainar [mailto:aarumuga@hotmail.com]
> Sent: Tuesday, May 16, 2006 9:47 AM
> To: Brian McGahan; D R; Mark Lasarko
> Cc: ccielab@groupstudy.com
> Subject: Re: ip route to itself - rephrased
>
> Hi Brian ,
>
> I think there is catch here . Under this circumstances you will two
routes
>
> 1) One is a connected route for 172.242.246.208/29
> 2) Second route will for 170.242.246.212/32
>
> Pls. note : Connected route might be having least admin distance but
in
> case
> you have more specific route you will still find the route getting
> installed
> in the Routing table .
>
> Thanks and Regards
> Arun
>
> ----- Original Message -----
> From: "Brian McGahan" <bmcgahan@internetworkexpert.com>
> To: "D R" <deep.ratan@gmail.com>; "Mark Lasarko"
<mlasarko@co.ba.md.us>
> Cc: <ccielab@groupstudy.com>
> Sent: Monday, May 15, 2006 9:57 PM
> Subject: RE: ip route to itself - rephrased
>
>
> > If 170.242.246.212 is directly connected you can't override it
> > with a static route. The lowest administrative distance a static
route
> > can have is 1. A connected interface has an administrative distance
of
> > 0. Look at the output of the "debug ip routing" after you install
the
> > route and see what the router says.
> >
> > HTH,
> >
> > Brian McGahan, CCIE #8593
> > bmcgahan@internetworkexpert.com
> >
> > Internetwork Expert, Inc.
> > http://www.InternetworkExpert.com
> > Toll Free: 877-224-8987 x 705
> > Outside US: 775-826-4344 x 705
> > 24/7 Support: http://forum.internetworkexpert.com
> > Live Chat: http://www.internetworkexpert.com/chat/
> >
> >
> > > -----Original Message-----
> > > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
Behalf
> > Of D
> > > R
> > > Sent: Monday, May 15, 2006 11:01 AM
> > > To: Mark Lasarko
> > > Cc: ccielab@groupstudy.com
> > > Subject: Re: ip route to itself - rephrased
> > >
> > > Yeah of course I've tried it. The router accepts the command. It's
a
> > 2600
> > > series router running 12.1(19).
> > >
> > > Rephrase:
> > >
> > >
> > > ip route 170.242.246.73 255.255.255.255 170.242.246.212*
> > > ip route 170.242.246.212 255.255.255.255 170.242.246.212*
> > >
> > > interface FastEthernet0/1
> > > description Bank LAN Connection
> > > ip address 170.242.246.210 255.255.255.248
> > > speed 100
> > > full-duplex
> > >
> > > 170.242.246.212 is a firewall directly connected to fa0/1.
> > >
> > > Will the command in* bold*:
> > >
> > > A) cause traffic intended for 170.242.246.73 to go into a black
hole?
> > > B) cause traffic returning from 170.242.246.212 to go into a loop?
> > > C) have no effect, traffic intended for 170.242.246.73 will go out
> > FA0/1
> > > as
> > > per normal routing process
> > > D) other
> > >
> > > Again, don't question the validity/purpose/legitimacy of the
command.
> > I'm
> > > interested to know what effect it has.
> > >
> > >
> > > thanks very much, DR
> > >
> > >
> > >
> > > On 5/15/06, Mark Lasarko <mlasarko@co.ba.md.us> wrote:
> > > >
> > > > ? Have you actually tried this...
> > > > AFAIK the router should bark at you :(
> > > > "%Invalid next hop address" or similar message.
> > > > ~M
> > > >
> > > >
> > > > >>> "D R" <deep.ratan@gmail.com> 05/15/06 8:38 AM >>>
> > > > Gents, Rudimentary question:
> > > >
> > > > FA0/1 is configured with 10.10.10.1 255.255.255.0 and is up/up.
> > > >
> > > > in global config mode:
> > > >
> > > > ip route 10.10.10.10 255.255.255.255 10.10.10.10
> > > >
> > > > The static route config above will:
> > > >
> > > > A) cause a routing loop
> > > > B) have no effect
> > > >
> > > >
> >
This archive was generated by hypermail 2.1.4 : Thu Jun 01 2006 - 06:33:21 ART