I think the only time I've seen that is when I ping through a router that doesn't have the next-hop IP (according to its route tables) in its ARP table, plus doing an ARP request doesn't come back with anything either. In other words, I don't think I've ever seen an "ICMP destination unreachable" coming back from a ping within a single segment; only across a router.
Semi-obvious stuff to check:
Do both the clients have an IP? (ip addr show, assuming iproute2 is installed)
Do both clients have the correct nameservers? (/etc/resolv.conf, already mentioned)
Do both clients have the same /etc/nsswitch.conf file, so that glibc's gethostbyname() and getaddrinfo() will use the DNS server, instead of (e.g.) local files?
What do the route tables look like, if you're trying to ping or do DNS across a router? (ip route show) |
