Pinging Subnet Address - Is this normal?

hitmen

Q1

R4#ping 172.16.34.0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.34.0, timeout is 2 seconds:
Reply to request 0 from 172.16.34.3, 68 ms
Reply to request 1 from 172.16.34.3, 1 ms
Reply to request 2 from 172.16.34.3, 8 ms


I am pinging the subnet address 172.16.34.0 255.255.255.0
Is the output like this normal?


Q2
What is the difference if I put no auto-summary vs auto-summary in discontiguous network?
Will the packets just go both ways?
Does it affect pinging or QoS in any way?
I only know that I have to put it to no auto-summary to be "safe"

paq7512

Your network 172.16.34.3 classful network is 172.16.0.0 / 16 when you do no auto-summary that means send subnet info to my neighbor, if you did not do that and have another router on say 172.16.35.0 traffic will most likely go to both routers and you could lose half the traffic, if a host in on a particular network and not the other, you could setup load balancing but that is another topic.

hitmen

I don't understand. Why doesn't the ping with 5 exclamation marks exist?

networker050184

Because you are pinging a broadcast address.

xXErebuS

networker050184 wrote: »

Because you are pinging a broadcast address.

Technically pinging a network address....

Depends on switch / IOS, I get 5 exclamation points when doing it in my environment. Are you using a real switch or virtual? PT and GNS are not good tests for granular things.

powmia

Ever see the command "ip broadcast-address 0.0.0.0" in a router? Networker is right, your network ID is also a broadcast address. This isn't RFC compliant, so not all devices allow this anymore.

hitmen

I am using GNS3. Is the outpur normal then?

Danielh22185

Yes you are pinging the broadcast address so my guess is you are getting the return from the .3 address because it is the only address in that subnet that can return the ICMP response.