Dual Network Gateway on CentOS 6.7

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0

I have dual NIC machine running CentOS 6.7 and asterisk. First NIC is for LAN & Internet connectivity and second is for trunk provider’s connectivity. Both of these have gateways configured. I don’t seem to be able to access the Internet as the traffic is routed thru the Second NIC’s gateway, also the second NIC is taken as default route by the kernel. I do not understand how default gateway is assigned in this case and what correction should I do.

Eth0 Config:

DEVICE=eth0
TYPE=Ethernet
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=static
IPADDR=192.168.0.1
NETMASK=255.255.255.0
GATEWAY=192.168.0.100
DNS1=8.8.8.8
DNS2=8.8.4.4

Eth1 Config:

DEVICE=eth1
TYPE=Ethernet
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=static
IPADDR=10.165.11.139
NETMASK=255.255.255.248
GATEWAY=10.165.11.137

Ping Internet

ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
From 10.165.11.137 icmp_seq=1 Destination Net Unreachable

Ping SIP Trunk

ping 10.232.130.170
PING 10.232.130.170 (10.232.130.170) 56(84) bytes of data.
64 bytes from 10.232.130.170 (10.232.130.170): icmp_seq=1 ttl=253 time=3.14 ms

Routing Table

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.165.11.136   *               255.255.255.248 U     0      0        0 eth1
192.168.0.0     *               255.255.255.0   U     0      0        0 eth0
link-local      *               255.255.0.0     U     1002   0        0 eth0
link-local      *               255.255.0.0     U     1003   0        0 eth1
default         10.165.11.137   0.0.0.0         UG    0      0        0 eth1

share|improve this question

    0

    I have dual NIC machine running CentOS 6.7 and asterisk. First NIC is for LAN & Internet connectivity and second is for trunk provider’s connectivity. Both of these have gateways configured. I don’t seem to be able to access the Internet as the traffic is routed thru the Second NIC’s gateway, also the second NIC is taken as default route by the kernel. I do not understand how default gateway is assigned in this case and what correction should I do.

    Eth0 Config:

    DEVICE=eth0
    TYPE=Ethernet
    ONBOOT=yes
    NM_CONTROLLED=yes
    BOOTPROTO=static
    IPADDR=192.168.0.1
    NETMASK=255.255.255.0
    GATEWAY=192.168.0.100
    DNS1=8.8.8.8
    DNS2=8.8.4.4
    

    Eth1 Config:

    DEVICE=eth1
    TYPE=Ethernet
    ONBOOT=yes
    NM_CONTROLLED=no
    BOOTPROTO=static
    IPADDR=10.165.11.139
    NETMASK=255.255.255.248
    GATEWAY=10.165.11.137
    

    Ping Internet

    ping 8.8.8.8
    PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
    From 10.165.11.137 icmp_seq=1 Destination Net Unreachable
    

    Ping SIP Trunk

    ping 10.232.130.170
    PING 10.232.130.170 (10.232.130.170) 56(84) bytes of data.
    64 bytes from 10.232.130.170 (10.232.130.170): icmp_seq=1 ttl=253 time=3.14 ms
    

    Routing Table

    Kernel IP routing table
    Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
    10.165.11.136   *               255.255.255.248 U     0      0        0 eth1
    192.168.0.0     *               255.255.255.0   U     0      0        0 eth0
    link-local      *               255.255.0.0     U     1002   0        0 eth0
    link-local      *               255.255.0.0     U     1003   0        0 eth1
    default         10.165.11.137   0.0.0.0         UG    0      0        0 eth1
    

    share|improve this question

      0

      0

      0

      I have dual NIC machine running CentOS 6.7 and asterisk. First NIC is for LAN & Internet connectivity and second is for trunk provider’s connectivity. Both of these have gateways configured. I don’t seem to be able to access the Internet as the traffic is routed thru the Second NIC’s gateway, also the second NIC is taken as default route by the kernel. I do not understand how default gateway is assigned in this case and what correction should I do.

      Eth0 Config:

      DEVICE=eth0
      TYPE=Ethernet
      ONBOOT=yes
      NM_CONTROLLED=yes
      BOOTPROTO=static
      IPADDR=192.168.0.1
      NETMASK=255.255.255.0
      GATEWAY=192.168.0.100
      DNS1=8.8.8.8
      DNS2=8.8.4.4
      

      Eth1 Config:

      DEVICE=eth1
      TYPE=Ethernet
      ONBOOT=yes
      NM_CONTROLLED=no
      BOOTPROTO=static
      IPADDR=10.165.11.139
      NETMASK=255.255.255.248
      GATEWAY=10.165.11.137
      

      Ping Internet

      ping 8.8.8.8
      PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
      From 10.165.11.137 icmp_seq=1 Destination Net Unreachable
      

      Ping SIP Trunk

      ping 10.232.130.170
      PING 10.232.130.170 (10.232.130.170) 56(84) bytes of data.
      64 bytes from 10.232.130.170 (10.232.130.170): icmp_seq=1 ttl=253 time=3.14 ms
      

      Routing Table

      Kernel IP routing table
      Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
      10.165.11.136   *               255.255.255.248 U     0      0        0 eth1
      192.168.0.0     *               255.255.255.0   U     0      0        0 eth0
      link-local      *               255.255.0.0     U     1002   0        0 eth0
      link-local      *               255.255.0.0     U     1003   0        0 eth1
      default         10.165.11.137   0.0.0.0         UG    0      0        0 eth1
      

      share|improve this question

      I have dual NIC machine running CentOS 6.7 and asterisk. First NIC is for LAN & Internet connectivity and second is for trunk provider’s connectivity. Both of these have gateways configured. I don’t seem to be able to access the Internet as the traffic is routed thru the Second NIC’s gateway, also the second NIC is taken as default route by the kernel. I do not understand how default gateway is assigned in this case and what correction should I do.

      Eth0 Config:

      DEVICE=eth0
      TYPE=Ethernet
      ONBOOT=yes
      NM_CONTROLLED=yes
      BOOTPROTO=static
      IPADDR=192.168.0.1
      NETMASK=255.255.255.0
      GATEWAY=192.168.0.100
      DNS1=8.8.8.8
      DNS2=8.8.4.4
      

      Eth1 Config:

      DEVICE=eth1
      TYPE=Ethernet
      ONBOOT=yes
      NM_CONTROLLED=no
      BOOTPROTO=static
      IPADDR=10.165.11.139
      NETMASK=255.255.255.248
      GATEWAY=10.165.11.137
      

      Ping Internet

      ping 8.8.8.8
      PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
      From 10.165.11.137 icmp_seq=1 Destination Net Unreachable
      

      Ping SIP Trunk

      ping 10.232.130.170
      PING 10.232.130.170 (10.232.130.170) 56(84) bytes of data.
      64 bytes from 10.232.130.170 (10.232.130.170): icmp_seq=1 ttl=253 time=3.14 ms
      

      Routing Table

      Kernel IP routing table
      Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
      10.165.11.136   *               255.255.255.248 U     0      0        0 eth1
      192.168.0.0     *               255.255.255.0   U     0      0        0 eth0
      link-local      *               255.255.0.0     U     1002   0        0 eth0
      link-local      *               255.255.0.0     U     1003   0        0 eth1
      default         10.165.11.137   0.0.0.0         UG    0      0        0 eth1
      

      centos networking route asterisk sip

      share|improve this question

      share|improve this question

      share|improve this question

      share|improve this question

      edited Jan 1 at 21:46

      Rui F Ribeiro

      39.5k1479132

      39.5k1479132

      asked Jan 1 at 18:29

      user1263746user1263746

      2013517

      2013517

          1 Answer
          1

          active

          oldest

          votes

          1

          Edit the eth1 config file and comment out/delete the gateway line and restart network service as follows:

          service network restart
          

          Now you should see 192.168.0.100 as your default router and everything should be working as expected.

          By default, all the traffic related with the subnet of the eth1 interface, will go through that interface because the kernel will create that entry.

          It’s good to mention that all the traffic (except 10.165.11.136/255.255.255.248), will go through your default gateway, but in case you want to route some specific traffic through eth1 interface you can do as follows:

          Runtime:

          ip route add X.X.X.X/32 via 10.165.11.137 dev eth1
          

          Permanent:

          1. Create the file /etc/sysconfig/network-script/route-eth1
          2. Add a line like this

            X.X.X.X/32 via 10.165.11.137

          3. Restart network service to apply

            service network restart

          I hope this helps.

          share|improve this answer

          • I tried removed gateway from eth1, I can ping 10.165.11.137 (gateway), but 10.232.130.170 (remote host) is surprisingly not reachable. ip route add X.X.X.X/32 via 10.165.11.137 dev eth1, how do I make this generic for all 255 hosts of 10.232.130.X subnet?

            – user1263746
            Jan 1 at 20:00

          • @user1263746 The IP 10.232.130.170 is out the subnet of eth1 interface. You should add a route. Something like this: ip route add 10.232.130.0/24 via 10.165.11.137 dev eth1.

            – Manuel Florian
            Jan 1 at 20:11

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          1 Answer
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          1 Answer
          1

          active

          oldest

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          active

          oldest

          votes

          active

          oldest

          votes

          1

          Edit the eth1 config file and comment out/delete the gateway line and restart network service as follows:

          service network restart
          

          Now you should see 192.168.0.100 as your default router and everything should be working as expected.

          By default, all the traffic related with the subnet of the eth1 interface, will go through that interface because the kernel will create that entry.

          It’s good to mention that all the traffic (except 10.165.11.136/255.255.255.248), will go through your default gateway, but in case you want to route some specific traffic through eth1 interface you can do as follows:

          Runtime:

          ip route add X.X.X.X/32 via 10.165.11.137 dev eth1
          

          Permanent:

          1. Create the file /etc/sysconfig/network-script/route-eth1
          2. Add a line like this

            X.X.X.X/32 via 10.165.11.137

          3. Restart network service to apply

            service network restart

          I hope this helps.

          share|improve this answer

          • I tried removed gateway from eth1, I can ping 10.165.11.137 (gateway), but 10.232.130.170 (remote host) is surprisingly not reachable. ip route add X.X.X.X/32 via 10.165.11.137 dev eth1, how do I make this generic for all 255 hosts of 10.232.130.X subnet?

            – user1263746
            Jan 1 at 20:00

          • @user1263746 The IP 10.232.130.170 is out the subnet of eth1 interface. You should add a route. Something like this: ip route add 10.232.130.0/24 via 10.165.11.137 dev eth1.

            – Manuel Florian
            Jan 1 at 20:11

          1

          Edit the eth1 config file and comment out/delete the gateway line and restart network service as follows:

          service network restart
          

          Now you should see 192.168.0.100 as your default router and everything should be working as expected.

          By default, all the traffic related with the subnet of the eth1 interface, will go through that interface because the kernel will create that entry.

          It’s good to mention that all the traffic (except 10.165.11.136/255.255.255.248), will go through your default gateway, but in case you want to route some specific traffic through eth1 interface you can do as follows:

          Runtime:

          ip route add X.X.X.X/32 via 10.165.11.137 dev eth1
          

          Permanent:

          1. Create the file /etc/sysconfig/network-script/route-eth1
          2. Add a line like this

            X.X.X.X/32 via 10.165.11.137

          3. Restart network service to apply

            service network restart

          I hope this helps.

          share|improve this answer

          • I tried removed gateway from eth1, I can ping 10.165.11.137 (gateway), but 10.232.130.170 (remote host) is surprisingly not reachable. ip route add X.X.X.X/32 via 10.165.11.137 dev eth1, how do I make this generic for all 255 hosts of 10.232.130.X subnet?

            – user1263746
            Jan 1 at 20:00

          • @user1263746 The IP 10.232.130.170 is out the subnet of eth1 interface. You should add a route. Something like this: ip route add 10.232.130.0/24 via 10.165.11.137 dev eth1.

            – Manuel Florian
            Jan 1 at 20:11

          1

          1

          1

          Edit the eth1 config file and comment out/delete the gateway line and restart network service as follows:

          service network restart
          

          Now you should see 192.168.0.100 as your default router and everything should be working as expected.

          By default, all the traffic related with the subnet of the eth1 interface, will go through that interface because the kernel will create that entry.

          It’s good to mention that all the traffic (except 10.165.11.136/255.255.255.248), will go through your default gateway, but in case you want to route some specific traffic through eth1 interface you can do as follows:

          Runtime:

          ip route add X.X.X.X/32 via 10.165.11.137 dev eth1
          

          Permanent:

          1. Create the file /etc/sysconfig/network-script/route-eth1
          2. Add a line like this

            X.X.X.X/32 via 10.165.11.137

          3. Restart network service to apply

            service network restart

          I hope this helps.

          share|improve this answer

          Edit the eth1 config file and comment out/delete the gateway line and restart network service as follows:

          service network restart
          

          Now you should see 192.168.0.100 as your default router and everything should be working as expected.

          By default, all the traffic related with the subnet of the eth1 interface, will go through that interface because the kernel will create that entry.

          It’s good to mention that all the traffic (except 10.165.11.136/255.255.255.248), will go through your default gateway, but in case you want to route some specific traffic through eth1 interface you can do as follows:

          Runtime:

          ip route add X.X.X.X/32 via 10.165.11.137 dev eth1
          

          Permanent:

          1. Create the file /etc/sysconfig/network-script/route-eth1
          2. Add a line like this

            X.X.X.X/32 via 10.165.11.137

          3. Restart network service to apply

            service network restart

          I hope this helps.

          share|improve this answer

          share|improve this answer

          share|improve this answer

          answered Jan 1 at 19:18

          Manuel FlorianManuel Florian

          364

          364

          • I tried removed gateway from eth1, I can ping 10.165.11.137 (gateway), but 10.232.130.170 (remote host) is surprisingly not reachable. ip route add X.X.X.X/32 via 10.165.11.137 dev eth1, how do I make this generic for all 255 hosts of 10.232.130.X subnet?

            – user1263746
            Jan 1 at 20:00

          • @user1263746 The IP 10.232.130.170 is out the subnet of eth1 interface. You should add a route. Something like this: ip route add 10.232.130.0/24 via 10.165.11.137 dev eth1.

            – Manuel Florian
            Jan 1 at 20:11

          • I tried removed gateway from eth1, I can ping 10.165.11.137 (gateway), but 10.232.130.170 (remote host) is surprisingly not reachable. ip route add X.X.X.X/32 via 10.165.11.137 dev eth1, how do I make this generic for all 255 hosts of 10.232.130.X subnet?

            – user1263746
            Jan 1 at 20:00

          • @user1263746 The IP 10.232.130.170 is out the subnet of eth1 interface. You should add a route. Something like this: ip route add 10.232.130.0/24 via 10.165.11.137 dev eth1.

            – Manuel Florian
            Jan 1 at 20:11

          I tried removed gateway from eth1, I can ping 10.165.11.137 (gateway), but 10.232.130.170 (remote host) is surprisingly not reachable. ip route add X.X.X.X/32 via 10.165.11.137 dev eth1, how do I make this generic for all 255 hosts of 10.232.130.X subnet?

          – user1263746
          Jan 1 at 20:00

          I tried removed gateway from eth1, I can ping 10.165.11.137 (gateway), but 10.232.130.170 (remote host) is surprisingly not reachable. ip route add X.X.X.X/32 via 10.165.11.137 dev eth1, how do I make this generic for all 255 hosts of 10.232.130.X subnet?

          – user1263746
          Jan 1 at 20:00

          @user1263746 The IP 10.232.130.170 is out the subnet of eth1 interface. You should add a route. Something like this: ip route add 10.232.130.0/24 via 10.165.11.137 dev eth1.

          – Manuel Florian
          Jan 1 at 20:11

          @user1263746 The IP 10.232.130.170 is out the subnet of eth1 interface. You should add a route. Something like this: ip route add 10.232.130.0/24 via 10.165.11.137 dev eth1.

          – Manuel Florian
          Jan 1 at 20:11

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