Cannot ping gateway

 
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Operating Systems Linux Red Hat Cannot ping gateway
# 1  
Old 05-17-2010
Cannot ping gateway

I know the subject line is very similar to: destination host unreachable

but the problem with my machine appears to be somewhat different from that thread. apologies if I missed something from there.

We recently moved a machine physically and from one subnet to another . I used `system-config-network-tui` to reconfigure the IP and gateway (I also, tried by manually editing /etc/sysconfig/network-scripts/ifcfg-eth* files but without success). Ever since I'm not able to ping the new gateway. I get "Destination Host Unreachable".

Here is my config:

Code:
# ifconfig -a

eth0      Link encap:Ethernet  HWaddr 00:03:47:D5:AB:6D  
          inet addr:10.8.10.40  Bcast:10.8.11.255  Mask:255.255.254.0
          UP BROADCAST MULTICAST  MTU:1500  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:1000 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

eth1      Link encap:Ethernet  HWaddr 00:03:47:D5:AB:6E  
          BROADCAST MULTICAST  MTU:1500  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:1000 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

eth2      Link encap:Ethernet  HWaddr 00:07:E9:10:CD:4A  
          UP BROADCAST MULTICAST  MTU:1500  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:1000 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)
          Base address:0x2800 Memory:fea80000-feaa0000 

eth3      Link encap:Ethernet  HWaddr 00:03:47:AE:4F:89  
          UP BROADCAST MULTICAST  MTU:1500  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:1000 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)
          Memory:fea60000-fea80000 

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:1745 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1745 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:2763244 (2.6 MiB)  TX bytes:2763244 (2.6 MiB)

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 -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.8.10.0       0.0.0.0         255.255.254.0   U     0      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     0      0        0 eth0
0.0.0.0         10.8.10.1       0.0.0.0         UG    0      0        0 eth0

A few things that I notice in the output of `ifconfig` is that, it doesn't say 'RUNNING' on the line " UP BROADCAST MULTICAST MTU:1500 Metric:1" (obviously) and secondly, the line which shows the base address and the memory assigned is missing in eth0 (note that it is present for eth2. i also tried reconfiguring the ip and gateway to eth2 instead but the result was same).

here is my ifcfg-eth0:
Code:
# cat /etc/sysconfig/network-scripts/ifcfg-eth0 
# Please read /usr/share/doc/initscripts-*/sysconfig.txt
# for the documentation of these parameters.
DEVICE=eth0
BOOTPROTO=none
BROADCAST=10.8.11.255
HWADDR=00:03:47:d5:ab:6d
IPADDR=10.8.10.40
NETMASK=255.255.254.0
NETWORK=10.8.10.0
ONBOOT=yes
TYPE=Ethernet
USERCTL=no
IPV6INIT=no
PEERDNS=yes
GATEWAY=10.8.10.1

What am I missing. Any help is greatly appreciated. I've spent almost 2 days now without any success.
Code:
# ping 127.0.0.1
PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.189 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.031 ms
64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.052 ms

# ping 10.8.10.40
PING 10.8.10.40 (10.8.10.40) 56(84) bytes of data.
64 bytes from 10.8.10.40: icmp_seq=1 ttl=64 time=0.103 ms
64 bytes from 10.8.10.40: icmp_seq=2 ttl=64 time=0.058 ms

# ping 10.8.10.1
PING 10.8.10.1 (10.8.10.1) 56(84) bytes of data.
From 10.8.10.40 icmp_seq=2 Destination Host Unreachable
From 10.8.10.40 icmp_seq=3 Destination Host Unreachable


---------- Post updated at 12:39 PM ---------- Previous update was at 12:23 PM ----------

I missed mentioning before that I can't even ping other machines in the same subnet
Code:
# ping 10.8.10.33
PING 10.8.10.33 (10.8.10.33) 56(84) bytes of data.
From 10.8.10.40 icmp_seq=1 Destination Host Unreachable
From 10.8.10.40 icmp_seq=2 Destination Host Unreachable
From 10.8.10.40 icmp_seq=3 Destination Host Unreachable

10.8.10.33 is up and running and I can ping from other machines.

Moderator's Comments:
Mod Comment Please use code tags


---------- Post updated at 03:16 PM ---------- Previous update was at 12:39 PM ----------

Please ignore my post. Eth0 port was bad. I used eth1 instead. It works well. Lessons learnt:
1. when ifconfig says UP but RUNNING is missing from the line, check the cable
2. use ethtool which tells clearly about the link status: " Link detected: yes|no" (last line in the output)
3. try to be physically available in the lab. It saves a lot of time.

---------- Post updated at 03:18 PM ---------- Previous update was at 03:16 PM ----------

This thread may be closed. My apologies to those who spent time reading the post. I should have checked my physical connections before posting.
# 2  
Old 05-26-2010
as per my knowledge....

just add routes


#route add default 10.8.10.1

then ping 10.8.10.1
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