Here’s a shell script to figure out what the IP4 gateway MAC address is, and to set that as the IP6 gateway MAC:<\/p>\n\n\n\n
#! \/bin\/bash\n\n# Get the v4 gateway IP address\nV4GW=$( ip route get 1 | sed 's\/.* via \/\/; s\/ .*\/\/; q' )\n# Get the MAC address for that\nV4MAC=$( ip neigh | grep -F -w \"$V4GW\" | sed 's\/.* lladdr \/\/; s\/ .*\/\/'; )\n# Get the IPv6 gateway IPv6 address\nV6GW=$( ip r g 1:: | sed 's\/.* via \/\/; s\/ .*\/\/; q' )\n# Check if the IPv6 gateway is in IP6-Neighbour-Discovery failure\nif ip n | grep -wF \"$V6GW\" | egrep -q 'INCOMPLETE|FAILED' ; then\n # Get the ip neigh[bour] string, e.g. dev eth0 lladdr 00:01:02:00:ff:ee \n NEIGHBOUR=$( ip neigh | grep -wF \"$V6GW\" | sed 's\/ *\\(INCOMPLETE\\|FAILED\\).*\/\/' )\n # delete the failed neighbour discovery\n ip neigh del $NEIGHBOUR\n # delete add a static neighbour\n ip neigh add $NEIGHBOUR lladdr $V4MAC\nfi<\/code><\/pre>\n\n\n\nThis was necessary for a machine where the gateway decided that responding to neighbour solicit requests was optional. (Still don’t know why it felt like that.)<\/p>\n","protected":false},"excerpt":{"rendered":"
Here’s a shell script to figure out what the IP4 gateway MAC address is, and to set that as the IP6 gateway MAC: This was necessary for a machine where the gateway decided that responding to neighbour solicit requests was … Continue reading