Can't ping bcast address

From: ccie2be (ccie2be@nyc.rr.com)
Date: Sat Mar 12 2005 - 20:11:49 GMT-3


Hi guys,

 

I don't get this. Maybe someone can fill me in.

 

There are a couple of strange things happening.

 

Notice in the debug output below, when I ping the broadcast address, the
debug shows dest address as 255.255.255.255

 

not 54.8.7.255 which is the address I actually pinged. Also, notice that
ping's to 54.8.7.254 work fine.

 

So, I have 2 questions:

 

Why is the router changing the broadcast address I'm pinging?

 

And, why isn't the ping to the bcast address working?

 

Also, notice that the config does include the broadcast keyword which I so
often forget.

 

Here's the config:

 

interface Loopback0

 ip address 54.8.7.6 255.255.255.0

!

interface ATM0/0

 no ip address

 no ip route-cache cef

 no atm ilmi-keepalive

!

interface ATM0/0.208 point-to-point

 pvc 0/208

  broadcast

  encapsulation aal5snap

  protocol ppp Virtual-Template1

 !

interface Virtual-Template1

 ip unnumbered Loopback0

 ppp chap hostname ROUTER6

 ppp chap password 0 CISCO

 

 

R6#p 54.8.7.254

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 54.8.7.254, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms

 

R6#p 54.8.7.255

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 54.8.7.255, timeout is 2 seconds:

.....

 

*Feb 10 21:27:58.687: IP: s=54.8.7.6 (Loopback0), d=255.255.255.255, len
100, un

routable

*Feb 10 21:27:59.735: IP: s=54.8.7.254 (Virtual-Access1), d=224.0.0.10, len
60,

unroutable

*Feb 10 21:28:00.687: IP: s=54.8.7.6 (local), d=255.255.255.255 (Loopback0),
len

 100, sending broad/multicast

*Feb 10 21:28:00.687: IP: s=54.8.7.6 (Loopback0), d=255.255.255.255, len
100, un

routable

*Feb 10 21:28:02.687: IP: s=54.8.7.6 (local), d=255.255.255.255 (Loopback0),
len

 100, sending broad/multicast

*Feb 10 21:28:02.687: IP: s=54.8.7.6 (Loopback0), d=255.255.255.255, len
100, un

routable

*Feb 10 21:28:04.687: IP: s=54.8.7.6 (local), d=255.255.255.255 (Loopback0),
len

 100, sending broad/multicast

*Feb 10 21:28:04.687: IP: s=54.8.7.6 (Loopback0), d=255.255.255.255, len
100, un

routable

 

TIA, Tim



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