December 9, 2016

Strange IPv4 Routing Issue on KVM Linux Node

I have primary /24 routed to a Centos 6 VPS node, KVM based system. I needed to add secondary /26 subnet specific to a VM for a client. I created the ifcfg-eth0-range0 file.

[root@kvm1 network-scripts]# cat ifcfg-eth0-range1
IPADDR_START=xxx.244.42.194
IPADDR_END=xxx.244.42.254
CLONENUM_START=0

Weird thing is, out of all 64 IPs, I can ping gateway fine and random IPs in between like 200, 196, etc but seems like the other half are getting "expired in transit" error oddly.
 

[root@kvm1 network-scripts]# cat ifcfg-br0
DEVICE=br0
TYPE=Bridge
BOOTPROTO=static
IPADDR=xxx.xxx.200.2
NETMASK=255.255.255.0
GATEWAY=xxx.xxx.200.1
ONBOOT=yes

[root@kvm1 network-scripts]# cat ifcfg-br0
DEVICE=br0
TYPE=Bridge
BOOTPROTO=static
IPADDR=xxx.xxx.200.2
NETMASK=255.255.255.0
GATEWAY=xxx.xxx.200.1
ONBOOT=yes

[root@kvm1 network-scripts]# cat ifcfg-eth0
DEVICE=eth0
HWADDR=00:25:90:A1:76:06
TYPE=Ethernet
UUID=187bd7f3-7ee1-4706-9489-1097cee44b3a
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=static
BRIDGE=br0

[root@kvm1 network-scripts]# cat ifcfg-eth0-range0
IPADDR_START=xxx.xxx.200.2
IPADDR_END=xxx.xxx.200.128
CLONENUM_START=0

Ran service network restart after and still can't ping all IPs, just random in between ones out of the /26.

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