ICMP Questions

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Guest

Hi, when you ping a remote host, if following message received, what they
mean and what may be the causes or problems?

"Requested timed out"
"Destination host unreachable"
"Reply from w.x.y.z - Destination host unreachable"
"Reply from w.x.y.z - TTL expired in transit"

Many thanks
Sultan
 
These links may help

routing issues on vpn
TTL expired in transit and Destination host unreachable ... From the server, you
receive "Destination host unreachable" when ping outside IP. ...
www.chicagotech.net/routingissuesonvpn.htm

troubleshooting ping issues
Host is unreachable Ping lists a public IP instead of private IP ... Reply from
209.165.105.129: Destination net unreachable. ...
www.chicagotech.net/troubleshootingping.htm

routing issues on vpn
TTL expired in transit and Destination host unreachable ... You receive Time out
or "Reply from xxxx: TTL expired in transit" when ping the server from ....
www.chicagotech.net/routingissuesonvpn.htm

troubleshooting ping issues
Hardware Error Host is unreachable Ping lists a public IP instead of private IP
Receiving a reply from a different IP TTL expired in transit ...
www.chicagotech.net/troubleshootingping.htm


Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on http://www.HowToNetworking.com

Homework?
 
No! Just trying to understand reply messages from ping and possible causes.

I got a test bed setup, tring to ping a IP addresses which has not been
allocated to a workstation yet. But the reply comes back with "request timed
out" should it say "Destination host unreachable"?

Many Thanks for look at the post.
Regards,
Sultan
 
Thanks Robert,

I shall look at the links you mentioned.

What would happen if you have following setup.

Workstation (a) --->SW1------>R1 -----> Sw2------>R2---->SW3----> R3--->
SW4----> Workstation (b). If the link is broken at R2----->SW3. When you ping
workstation b from a, what reply message should you get back.

I think "Reply from [router interface IP address] - Destination host
unreachable". Is this correct?

I do not have any routers and they cost too!!!

Many thanks for your reply.

Regards,
Sultan
 
There are a lot of assumptions there, but generally, I'd say you are right.
The switches don't matter one bit. SO if router 2 knows that the network it
is looking for is on the interface connected to router 3, and that interface
is down, it should return "destination host unreachable".

Shakey said:
Thanks Robert,

I shall look at the links you mentioned.

What would happen if you have following setup.

Workstation (a) --->SW1------>R1 -----> Sw2------>R2---->SW3----> R3--->
SW4----> Workstation (b). If the link is broken at R2----->SW3. When you
ping
workstation b from a, what reply message should you get back.

I think "Reply from [router interface IP address] - Destination host
unreachable". Is this correct?

I do not have any routers and they cost too!!!

Many thanks for your reply.

Regards,
Sultan

Robert L said:
These links may help

routing issues on vpn
TTL expired in transit and Destination host unreachable ... From the
server, you
receive "Destination host unreachable" when ping outside IP. ...
www.chicagotech.net/routingissuesonvpn.htm

troubleshooting ping issues
Host is unreachable Ping lists a public IP instead of private IP ...
Reply from
209.165.105.129: Destination net unreachable. ...
www.chicagotech.net/troubleshootingping.htm

routing issues on vpn
TTL expired in transit and Destination host unreachable ... You receive
Time out
or "Reply from xxxx: TTL expired in transit" when ping the server from
....
www.chicagotech.net/routingissuesonvpn.htm

troubleshooting ping issues
Hardware Error Host is unreachable Ping lists a public IP instead of
private IP
Receiving a reply from a different IP TTL expired in transit ...
www.chicagotech.net/troubleshootingping.htm


Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on
http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on
http://www.HowToNetworking.com

Homework?
Click to expand...
Click to expand...
 
If an IP address is on a valid network with a route to it, you will get a
"request timed out" (just as you would to a ping on your local subnet).

....kurt
 
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