Duplicate first hop (but network seems fine)
I am running pfSense 2.1 and have come across a strange situation that I would like to understand better.
My pfSense box routes between my LAN (192.168.0.0/24) and my WAN/ISP (an Ethernet connection to a cable modem). The LAN interface is 192.168.0.250 and the WAN interface has the public IP that my ISP assigns using DHCP. The pfSense box performs NAT on traffic leaving my LAN.
Everything seems fine, but I spotted this weirdness when running a traceroute from a box on my LAN. It is repeatable from any box on the LAN to any destination:
traceroute to www.google.com (188.8.131.52), 30 hops max, 60 byte packets 1 192.168.0.250 0.304 ms 0.530 ms 0.515 ms 2 192.168.0.250 9.214 ms 10.322 ms 10.319 ms 3 (public internet) 10.570 ms 10.563 ms 10.536 ms ...
i.e. for some reason my pfSense box is showing twice, as the first and second hop. The timings suggest the packet is actually going somewhere between hop 1 and hop 2 though.
Routing table (using 184.108.40.206 as my public WAN IP and 220.127.116.11 as ISP gateway):
Destination Gateway Flags Refs Use Mtu Netif Expire default 18.104.22.168 UGS 0 749852 1500 em0 192.168.0.0/24 link#2 U 0 1400043 1500 em1 192.168.0.250 link#2 UHS 0 0 16384 lo0 22.214.171.124/24 link#1 U 0 32442 1500 em0 126.96.36.199 link#1 UHS 0 0 16384 lo0 127.0.0.1 link#6 UH 0 99 16384 lo0
Has anybody seen this before? My network seems to work fine, but I would like to figure out why this looks the way it does.
Thanks in advance for any advice.
A couple of days later and - without touching the pfSense box - this problem seems to have disappeared. Weird!