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Hi, I have 2(bcm5704 and bcm5703) nics with 4 diferent ip(eth0,1,2,3) on 2 different subnets (x.x.230.x and x.x.221.x). Problem is when our network Engineer shuts down one switch port, 2 ...
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  1. #1
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    suse-multiple nic's same subnets issue


    Hi,
    I have 2(bcm5704 and bcm5703) nics with 4 diferent ip(eth0,1,2,3) on 2 different subnets (x.x.230.x and x.x.221.x). Problem is when our network Engineer shuts down one switch port, 2 ip's on same subnet will go down.
    I am trying to setup these for redundancy if one of the ip's or switches go down, other will take over.
    I tried with different options with zoning and port forwarding, but it is not wotking for me.
    eth0-x.x.230.16 int zone vlan1
    eth1-x.x.221.1 ext.zone vlan2
    eth2-x.x.230.26 int zone vlan1
    eth3-x.x.221.11 ext.zone vlan2

    Please help.
    Thanks,

  2. #2
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    Just to clarify:
    You have four IPs on a machine with two NICs, and you want to switch the IPs to just one NIC if the other goes down?

    If so, what is your ifconfig -a output (and perhaps route -n, and /etc/mygate)? Also, how are you monitoring the uplink of each IP?

  3. #3
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    Quote Originally Posted by dayid View Post
    Just to clarify:
    You have four IPs on a machine with two NICs, and you want to switch the IPs to just one NIC if the other goes down?

    If so, what is your ifconfig -a output (and perhaps route -n, and /etc/mygate)? Also, how are you monitoring the uplink of each IP?
    Yes, Redundancy is important. The problem is when the engineer shutsdown the port 2 ip's on same subnet are going down, which is not right. ONly one should go down.
    eth0 Link encap:Ethernet HWaddr 00:13:21:B4:81:28
    inet addr:172.22.230.106 Bcast:172.22.230.255 Mask:255.255.255.0
    UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
    RX packets:243979 errors:0 dropped:0 overruns:0 frame:0
    TX packets:150669 errors:0 dropped:0 overruns:0 carrier:0
    collisions:0 txqueuelen:1000
    RX bytes:41525980 (39.6 Mb) TX bytes:18528900 (17.6 Mb)
    Interrupt:24

    eth1 Link encap:Ethernet HWaddr 00:13:21:B4:81:27
    inet addr:172.22.221.76 Bcast:172.22.221.255 Mask:255.255.255.0
    UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
    RX packets:25063 errors:0 dropped:0 overruns:0 frame:0
    TX packets:20686 errors:0 dropped:0 overruns:0 carrier:0
    collisions:0 txqueuelen:1000
    RX bytes:1948317 (1.8 Mb) TX bytes:1571878 (1.4 Mb)
    Interrupt:25

    eth2 Link encap:Ethernet HWaddr 00:17:08:4F:61:FE
    inet addr:172.22.230.206 Bcast:172.22.230.255 Mask:255.255.255.0
    UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
    RX packets:4231 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:443283 (432.8 Kb) TX bytes:0 (0.0 b)
    Interrupt:32

    eth3 Link encap:Ethernet HWaddr 00:17:08:4F:61:FD
    inet addr:172.22.221.176 Bcast:172.22.221.255 Mask:255.255.255.0
    UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
    RX packets:87962 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:28938714 (27.5 Mb) TX bytes:0 (0.0 b)
    Interrupt:33

    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:17438 errors:0 dropped:0 overruns:0 frame:0
    TX packets:17438 errors:0 dropped:0 overruns:0 carrier:0
    collisions:0 txqueuelen:0
    RX bytes:1929335 (1.8 Mb) TX bytes:1929335 (1.8 Mb)



    172.22.230.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
    172.22.230.0 0.0.0.0 255.255.255.0 U 0 0 0 eth2
    172.22.221.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
    172.22.221.0 0.0.0.0 255.255.255.0 U 0 0 0 eth3
    169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
    127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
    224.0.0.0 0.0.0.0 240.0.0.0 U 0 0 0 eth0
    0.0.0.0 172.22.230.1 0.0.0.0 UG 0 0 0 eth0

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  5. #4
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    Quote Originally Posted by mike1234 View Post
    Yes, Redundancy is important. The problem is when the engineer shutsdown the port 2 ip's on same subnet are going down, which is not right. ONly one should go down.
    [...]
    e
    Quote Originally Posted by dayid View Post
    [...]how are you monitoring the uplink of each IP?
    More to the point: What are you doing to manage the failover/changes of the IPs - since that is where your problems are?

  6. #5
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    Multiple IP's on the same subnet introduce a loop condition and ARP lookup problems. If you are not familiar with what these are, the best solution is to implement a *bond* via the Linux bonding driver. This will present one interface on the network that can provide failover, etc.

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    Quote Originally Posted by HROAdmin26 View Post
    Multiple IP's on the same subnet introduce a loop condition and ARP lookup problems. If you are not familiar with what these are, the best solution is to implement a *bond* via the Linux bonding driver. This will present one interface on the network that can provide failover, etc.
    Thanks. I was leaning towards that option, but was not sure. I will try creating bond0 and bond1 and test it. I assume, I will need 2 new ip addresses for bonding,right?

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