Dear Linux experts

i configuring new server in my center .. all server ping to my router gateway.cisco router 1941 and firewall asa 5505
my network configur
vi /etc/sysconfig/network-scritps/ifcfg-eth0

DEVICE=eth0
HWADDR=90:2B:34:9D:5F:96
TYPE=Ethernet
UUID=da566236-143f-4631-b4bf-4079cdf0e314
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=none
IPADDR=10.0.0.15
NETMASK=255.255.255.0
GATEWAY=10.0.0.1
DNS1=8.8.8.8
DNS2=8.8.4.4
it's not ping my router gatway ..all servers ping to gatway .. pleas help me ...
[root@star~]#ping 10.0.0.1
ping 10.0.0.1 (10.0.0.1) 56(84) bytes of data
form 10.0.0.15 icmp_seq=2 Destination Host Unreachable
form 10.0.0.15 icmp_seq=2 Destination Host Unreachable
form 10.0.0.15 icmp_seq=2 Destination Host Unreachable
form 10.0.0.15 icmp_seq=2 Destination Host Unreachable

and if you do a:

what do you get?

apart from above can you tell me what have you configured in /etc/resolv.conf
and ofcourse iptables -L

1 members found this post helpful.

They're trying to ping an IP address,. resolv.conf doesn't come into it.

1 members found this post helpful.

Dear Experts



[root@gold ~]#ip route
10.0.0.0/24 dev eth0 proto kernel scope link src 10.0.0.15
169.254.0.0/16 dev eth0 scope link metric 1002
default via 10.0.0.1 dev eth0



[root@gold ~]# vi /etc/resolv.conf
nameserver 8.8.8.8
nameserver 8.8.4.4


root@gold [~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 90:2b:34:9d:5f:96 brd ff:ff:ff:ff:ff:ff
inet 10.0.0.15/24 brd 10.0.0.255 scope global eth0
inet6 fe80::922b:34ff:fe9d:5f96/64 scope link
valid_lft forever preferred_lft forever


root@gold [~]# iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED
ACCEPT icmp -- anywhere anywhere
ACCEPT all -- anywhere anywhere
ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:ssh
REJECT all -- anywhere anywhere reject-with icmp-host-prohibited

Chain FORWARD (policy ACCEPT)
target prot opt source destination
REJECT all -- anywhere anywhere reject-with icmp-host-prohibited

Chain OUTPUT (policy ACCEPT)
target prot opt source destination






i checked every command output i will display an forum ..
some time ping to router gateway ip getting
ping: send msg: no buffer space available
after i will give command
root@gold [~]# ifconfig em3 down;ifconfig em3 up

after i will try ping to my router gateway same error

please help me ....



Thank you ..

You're getting an "unreachable" error from your own IP address. That means the TCP/IP stack your system is unable to find the MAC address of the IP address "10.0.0.1", which it expects to find on the local LAN since it belongs to the same IP network as 10.0.0.15/24.

If you run arp -an immediately after attempting to ping 10.0.0.1, you will probably see something like this:You should check your physical network connections. See that the link lights are on, and run ethtool eth0 to verify connectivity.

1 members found this post helpful.

so you are actually blocking all request explicitly without any condition!!! i dont think this is a issue but have a look on your network architecture first, everything applies specifically where it is needed.

normally reject rules should be put on top so that unnecessary traffic should filter first and then reach on further accept conditions.

check this link for more on iptables

Dear Ser Olmy

i run This cmd arp -an

my pc output : ? (10.0.0.1) at f8:72:ea:a7:fd:XX [ether] on eth0

the physical connection every thing fine .. i have two server ..this two server getting same error ...

In this server i installed window server that time getting internet ..ping to router gateway also ..

how to solve the problem ..please help me ..sir


Thank you..

please give me replay ..how to solve the problem ...
please sir ...

Thank you

Let me see if I understand this:

1. Your server has the IP address 10.0.0.15 with a netmask of 255.255.255.0.
   
   
2. Your router has the IP address 10.0.0.1 with a netmask of 255.255.255.0.
   
   
3. If you ping the router (10.0.0.1) from the server (10.0.0.15), you get a "destination host unreachable" from 10.0.0.15 (the server itself).
   
   
4. After attempting to ping 10.0.0.1, arp -an reveals that an ARP entry for 10.0.0.1 has indeed been created, pointing to f8:72:ea:a7:fd:<something> (no need to anonymize MAC addresses; the first three octets reveal it's a Cisco router)

Is the above ccorrect? Have you double-checked all the IP details on both the server and the router? If so, could you post the output from iptables-save -t filter and ifconfig on the server?

If that is the case, I would want to know what his switch config is. Because my Spider Senses are detecting a VLAN assignment issue.

Dear Experts

it is normal switch Dlink switch......

Thank you ..

Dear Ser Olmy

in my server ip address also change after i try to ping same error ...

i checked router also ... i assigned 10.0.0.15 to any other pc i getting internet .....please help me sir


Thank you

You said if you assign the ip to another computer you get internet. Have you tried plugging this ethernet cable into that computer that gets internet to make sure it is not the cable/port/nic?

Just for the giggles, can you temporarily shutdown iptables?

then check to see if you can ping your gateway,.. if you can, its iptables blocking you.. if not.. well,..

Dear szboardstretcher

getting same issue ..sir please help me sir



i have total 5 server ..when i install time didnot dispaly any thing ..
but this 2 server display like this
Trying to allocate 984 pages for VMLINUZ
linux=EFI SETUP=0X1017 SIZE 0X3D7E70




Thank you