From: Bit Gossip (bit.gossip@chello.nl)
Date: Fri Jul 06 2007 - 15:55:19 ART
Antonio,
usually I ping the network: router are so kind to reply :-)
Cheers,
bit.
R5#show ip route
Gateway of last resort is not set
150.1.0.0/16 is subnetted, 1 subnets
B 150.1.0.0 [20/0] via 1.1.35.3, 00:00:37
R5#ping 150.1.0.0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 150.1.0.0, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 8/8/12 ms
R5#ping 150.1.4.4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 150.1.4.4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 8/8/12 ms
R5#
----- Original Message -----
From: "Antonio Soares" <amsoares@netcabo.pt>
To: <ccielab@groupstudy.com>
Sent: Friday, July 06, 2007 9:39 PM
Subject: Reachability to Backbone Routes
> Hello group,
>
> I've been thinking about this for a while and i don't see an easy solution
> to it.
>
> Suppose that R1 is receiving some RIP routes from a Backbone router:
>
> +++++++++++++++++++++++++++++
> R1#sh ip route rip
> R 172.16.0.0/16 [120/4] via 200.200.200.254, 00:00:27, Ethernet1/0
> R 10.0.0.0/8 [120/4] via 200.200.200.254, 00:00:27, Ethernet1/0
> R 192.168.1.0/24 [120/4] via 200.200.200.254, 00:00:27, Ethernet1/0
> R1#
> +++++++++++++++++++++++++++++
>
> And then you are asked to have full reachability to these routes from all
> your routers including R1 of course.
>
> But the Backbone has some restrictions and you are not told which is the
> host portion of each route been announced:
>
> +++++++++++++++++++++++++++++
> BB1:
>
> !
> interface Ethernet0
> ip address 200.200.200.254 255.255.255.0
> ip access-group 101 in
> no ip unreachables
> no ip proxy-arp
> no cdp enable
> !
> access-list 101 deny icmp any 0.0.0.255 255.255.255.0
> access-list 101 deny icmp any 0.0.255.255 255.255.0.0
> access-list 101 deny icmp any 0.255.255.255 255.0.0.0
> access-list 101 permit ip any any
> !
> +++++++++++++++++++++++++++++
>
>
> What would you do to verify reachibility ? I thought, well with a class C
> is
> somewhat easy but time consuming. I will do a tcl script in order to ping
> all the 254 possible hosts:
>
> Foreach ip {
>
> ping 192.168.1.1
> ping 192.168.1.2
> ping 192.168.1.3
> (...)
> ping 192.168.1.254
> } {ping $ip}
>
>
> But for a class B i would need 65534 lines !!! And for a class A 16777214
> lines !!!!
>
> So the question that matters: in the real lab are we given the necessary
> information to verify reachability to the backbone routes ?
>
>
>
>
> Thanks,
> Antonio
>
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This archive was generated by hypermail 2.1.4 : Sat Aug 18 2007 - 08:17:40 ART