Differences between version 7 and previous revision of DestinationHostUnreachable.
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| Newer page: | version 7 | Last edited on Thursday, April 12, 2007 3:17:19 pm | by BenStaz | Revert |
| Older page: | version 6 | Last edited on Thursday, April 12, 2007 3:12:02 pm | by BenStaz | Revert |
@@ -1,5 +1,5 @@
[ICMP] reason subcode 0x1, used with [ICMP] reason code 0x3 to explain why a DestinationUnreachable message was sent.
-When a datagram is being forwarded, and reaches a router attached to the network a destination host is to be found on (i.e, the last hop router), and the route
to the host is down,
the host is not responding or does not respond on the service port in question,
a Host
Unreachable message is sent back.
+When a datagram is being forwarded, and reaches a router attached to the network a destination host is to be found on (i.e, the last hop router), and the router has ascertained that there is no path
to the destination
host then
the router must generate
a Destination
Unreachable
It is usally generated by a gateway when it does not have a route for the destination specified in the IP packet that caused the error. Often this reason is used when a router cannot contact the next hop router specified in it's routing table (ie. The next hop router is not responding to [ARP] requests).
