Ping error "Destination Host Unreachable" from the gateway
Hello all !
I'm having the following problem: I have a Fedora Core with 2 network cars: -> eth0 = connected to the Internet with INET_IP = xx.xx.xx.99 netmask=255.255.255.248 -> eth1 = connected to internal LAN with LAN_IP Conection with the internal LAN works great ! The problem is that conection with the internet gateway does not work... ip is GW_IP = xx.xx.xx.97 ! If use "arp " => for the internet connection says <incomplete> !!! Please see below some configuration and results to some commands: [root@xxxxx root]# ifconfig -a eth0 Link encap:Ethernet HWaddr xxxx inet addr: ..INET_IP.. Bcast:xxxx Mask:xxxx UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:845 errors:0 dropped:0 overruns:0 frame:0 TX packets:51 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:50700 (49.5 Kb) TX bytes:2142 (2.0 Kb) Interrupt:9 Base address:0xe400 eth1 Link encap:Ethernet HWaddr xxxx inet addr:LAN_IP Bcast:XXXX Mask:XXXX UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1684 errors:0 dropped:0 overruns:0 frame:0 TX packets:9984 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:166352 (162.4 Kb) TX bytes:648411 (633.2 Kb) Interrupt:12 Base address:0xe000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:50 errors:0 dropped:0 overruns:0 frame:0 TX packets:50 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:4923 (4.8 Kb) TX bytes:4923 (4.8 Kb) ------------------------------------------------------------------ [root@xxxx root]# route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface INET_NETADDR * xxxxx U 0 0 0 eth0 LAN_NETADDR * xxxxx U 0 0 0 eth1 127.0.0.0 * 255.0.0.0 U 0 0 0 lo default * 0.0.0.0 U 0 0 0 eth0 ------------------------------------------------------------------ [root@xxxx root]# netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface INET_IP_NETADDR 0.0.0.0 xxxxx U 0 0 0 eth0 LAN_NETADDR 0.0.0.0 xxxxx U 0 0 0 eth1 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 0.0.0.0 0.0.0.0 U 0 0 0 eth0 ------------------------------------------------------------------- [root@xxxxx root]# ping IP_GATEWAY PING IP_GATEWAY (IP_GATEWAY) 56(84) bytes of data. From INET_IP icmp_seq=0 Destination Host Unreachable From INET_IP icmp_seq=1 Destination Host Unreachable From INET_IP icmp_seq=2 Destination Host Unreachable --- IP_GATEWAY ping statistics --- 4 packets transmitted, 0 received, +3 errors, 100% packet loss, time 3020ms , pipe 4 --------------------------------------------------------------------- [root@xxxxx root]# ping IP_DNS PING IP_DNS (IP_DNS) 56(84) bytes of data. From INET_IP icmp_seq=0 Destination Host Unreachable From INET_IP icmp_seq=1 Destination Host Unreachable From INET_IP icmp_seq=2 Destination Host Unreachable --- IP_DNS ping statistics --- 4 packets transmitted, 0 received, +3 errors, 100% packet loss, time 3023ms , pipe 4 --------------------------------------------------------------------- ============================================================================== [root@xxxx root]# route add default gw xx.xx.xx.97 [root@xxxx root]# route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface xx.xx.xx.96 * 255.255.255.248 U 0 0 0 eth0 LAN_NET_ADDR * 255.255.255.0 U 0 0 0 eth1 127.0.0.0 * 255.0.0.0 U 0 0 0 lo default xx.xx.xx.97 0.0.0.0 UG 0 0 0 eth0 ---------------------------------------------------- [root@xxxx root]# ping xx.xx.xx.97 PING xx.xx.xx.97 (xx.xx.xx.97) 56(84) bytes of data. From xx.xx.xx.99 icmp_seq=0 Destination Host Unreachable From xx.xx.xx.99 icmp_seq=1 Destination Host Unreachable From xx.xx.xx.99 icmp_seq=2 Destination Host Unreachable --- xx.xx.xx.97 ping statistics --- 4 packets transmitted, 0 received, +3 errors, 100% packet loss, time 3024ms , pipe 4 ---------------------------------- [root@xxxx root]# arp -a ? (LAN_IP) at LAN_MAC [ether] on eth1 ? (xx.xx.xx.97) at <incomplete> on eth0 ================================================ [root@xxxx root]# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface xx.xx.xx.96 0.0.0.0 255.255.255.248 U 0 0 0 eth0 LAN_IP 0.0.0.0 255.255.255.0 U 0 0 0 eth1 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 xx.xx.xx.97 0.0.0.0 UG 1 0 0 eth0 --------------------------------------------- [root@xxxx root]# ping xx.xx.xx.97 PING xx.xx.xx.97 (xx.xx.xx.97) 56(84) bytes of data. From xx.xx.xx.99 icmp_seq=0 Destination Host Unreachable From xx.xx.xx.99 icmp_seq=1 Destination Host Unreachable From xx.xx.xx.99 icmp_seq=2 Destination Host Unreachable ^C --- xx.xx.xx.97 ping statistics --- 6 packets transmitted, 0 received, +3 errors, 100% packet loss, time 4999ms , pipe 4 ------------------------------------------------ [root@xxxx root]# mii-tool eth0: no autonegotiation, 10baseT-HD, link ok eth1: negotiated 100baseTx-FD, link ok ------------------------------------------------ [root@xxxx root]# mii-tool -F 100baseTx-FD eth0 [root@xxxx root]# mii-tool eth0: 100 Mbit, full duplex, no link eth1: negotiated 100baseTx-FD, link ok ----------------------------------------------- [root@xxxx root]# mii-tool -F 10baseT-HD eth0 [root@xxxx root]# mii-tool eth0: 10 Mbit, half duplex, link ok eth1: negotiated 100baseTx-FD, link ok ---------------------------------------------- [root@xxxx root]# ping xx.xx.xx.97 PING xx.xx.xx.97 (xx.xx.xx.97) 56(84) bytes of data. From xx.xx.xx.99 icmp_seq=0 Destination Host Unreachable From xx.xx.xx.99 icmp_seq=1 Destination Host Unreachable ------------------------------------------------------- |
man that's annoyingly hard to read with all that pointless censorship.. who cares what your hostname and internal ip is?? since when was a subnet mask classified information? :confused:
where are you getting this internet address from? it doesn't look like it's DHCP as you've no default gateway set on the route output. if it is dhcp then by definition your intenet gateway must be reachable as that's what gave you the IP lease. |
Well, kewpie...what you say is logical and I've always thought it was true until recently.
I've installed a few systems (Vector Linux SOHO 5.1, Debian, Mandriva Discovery 2006) and they all seem to have the same problem (apart from the user-me of course). I use DHCP. The system goes up. It asks the server for the settings, it receives it and configures ok but then there's no net, and I can't even ping dhcp server. What am I doing wrong? P.S. The net card works fine. I installed Slackware 11 for a moment and after kernel recompiling (DHCP support compiled into the kernel) all worked ok, internet available etc. Here are some outputs: #ifconfig -a eth0 Link encap:Ethernet HWaddr 00:A1:B0:00:xx:xx inet addr:192.168.42.54 Bcast:192.168.42.255 Mask:255.255.255.0 inet6 addr: fe80::2a1:b0ff:fe00:xxxx/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:11 errors:0 dropped:0 overruns:0 frame:0 TX packets:781 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1703 (1.6 KiB) TX bytes:47802 (46.6 KiB) Interrupt:9 Base address:0x4000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:774 errors:0 dropped:0 overruns:0 frame:0 TX packets:774 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:43272 (42.2 KiB) TX bytes:43272 (42.2 KiB) sit0 Link encap:IPv6-in-IPv4 NOARP MTU:1480 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) #route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.42.0 * 255.255.255.0 U 10 0 0 eth0 default 192.168.42.15 0.0.0.0 UG 10 0 0 eth0 #mii-tool eth0: negotiated 100baseTx-FD, link ok #ping 192.168.42.15 PING 192.168.42.15 (192.168.42.15) 56(84) bytes of data. From 192.168.42.54 icmp_seq=2 Destination Host Unreachable From 192.168.42.54 icmp_seq=3 Destination Host Unreachable From 192.168.42.54 icmp_seq=4 Destination Host Unreachable From 192.168.42.54 icmp_seq=6 Destination Host Unreachable From 192.168.42.54 icmp_seq=7 Destination Host Unreachable From 192.168.42.54 icmp_seq=8 Destination Host Unreachable --- 192.168.42.15 ping statistics --- 9 packets transmitted, 0 received, +6 errors, 100% packet loss, time 8000ms , pipe 3 |
ok, it's possible that the server is dropping ping requests, i think that would make a host unreachable scenario according to the ICMP RFC definitions. but if that is the case then you'd still have avalid arp table entry, so run "arp" and see if it shows it there. if it does then that is talking to you at some level.
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it came up empty. It executed but a command line was next.
And it won't ping any other hosts in the network (except for the lo and localhost). All the other machines (not too many of them) and the Slackware I mentioned had no problems with dropped pings. Would the internet be available even if the server was dropping ping requests? |
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