How can I get /proc/net/dev from vmcore?

My system(CentOS6) crashed, and I got a vmcore. Now I want to know how to get /proc/net/dev in vmcore, or how can I get net statistics counter data(e.g, netstat -s)? I trigger a crash on CentOS7, and I can find some counters after run net and struct commands: crash> net NET_DEVICE NAME IP ADDRESS(ES) ffff881053f97000 lo 127.0.0.1 ffff88084ece0000 eth0 xxx.xxx.xxx.xxx ffff88084e480000 eth1 xxx.xxx.xxx.xxx crash> struct net_device ffff88084ece0000 ...... stats = { rx_packets = 122192214759, tx_packets = 122785688757, rx_bytes = 140670240738618, tx_bytes = 136965095362827, rx_errors = 0, tx_errors = 0, rx_dropped = 0, ...... But it doesn't make sense in CentOS6, I just get 0 for all counters: crash> net NET_DEVICE NAME IP ADDRESS(ES) ffff881028a10020 lo 127.0.0.1 ffff8820253a4020 eth0 xxx.xxx.xxx.xxx ffff8820253a8020 eth1 xxx.xxx.xxx.xxx ...... stats = { rx_packets = 0, tx_packets = 0, rx_bytes = 0, tx_bytes = 0, rx_errors = 0, tx_errors = 0, rx_dropped = 0, ...... Does it mean that on CentOS6 net counters are NOT stored in memory? Thanks!