请问一下在SUSE Linux中traceroute 结果中的!N是什么意思？

xietong007

-bash-3.1# traceroute 172.29.75.147
traceroute to 172.29.75.147 (172.29.75.147), 30 hops max, 40 byte packets
1   (10.90.1.254)  0.178 ms  0.249 ms  0.334 ms
2   (10.90.2.1)  5.813 ms  6.550 ms  7.234 ms
3   (10.90.2.25)  1.431 ms !N  1.871 ms !N  2.257 ms !N

-bash-3.1# ping 172.29.75.147
PING 172.29.75.147 (172.29.75.147) 56(84) bytes of data.
From 10.90.2.25 icmp_seq=1 Destination Net Unreachable
From 10.90.2.25 icmp_seq=2 Destination Net Unreachable
From 10.90.2.25 icmp_seq=3 Destination Net Unreachable
From 10.90.2.25 icmp_seq=4 Destination Net Unreachable

--- 172.29.75.147 ping statistics ---
4 packets transmitted, 0 received, +4 errors, 100% packet loss, time 3000ms


测试2个网元之间的连通性，ping对端不通，traceroute的结果中包含!N，请问一下是什么意思？

谢谢！

ssffzz1

Net Unreachable

饭饭小鱼儿

帮顶，同想知道~~~