Why would your router ARP for an address that is not on the same subnet as any of your interfaces? From: MICE Discuss [mailto:MICE-DISCUSS@LISTS.IPHOUSE.NET] On Behalf Of Matthew Beckwell Sent: Thursday, August 16, 2018 5:01 PM To: MICE-DISCUSS@LISTS.IPHOUSE.NET Subject: Re: [MICE-DISCUSS] Routing of non-IX traffic I'm getting similar behavior as Frank. Like Doug, I only have 45.60.73.0/24 from transit connections. So a traceroute from my MICE interface should ARP and die (I would think).... When I traceroute to 45.60.73.16-- my router sends out an ARP request, as expected. But...I get ARP replies for 45.60.73.16 from these Cisco MACs (in the order they came into my interface): 00:23:33:c6:a0:c0206.108.255.50Cooperative Network Services (CNS)32609 e4:aa:5d:83:73:06206.108.255.47IVDesk393639 88:43:e1:00:f2:10206.108.255.18Consolidated Communications12042 b0:aa:77:33:7b:03206.108.255.79Gigamonster, LLC31939 3c:08:f6:81:6e:a5206.108.255.46OneNetUSA46131 00:1d:e5:c0:78:c3206.108.255.5Implex21709 54:75:d0:e6:08:30206.108.255.106Nuvera Communications23465 00:11:5d:82:6c:00206.108.255.80Future Technologies26451 Proxy ARP (or something like it)? CNS seems to be consistently coming in first place when I clear my ARP entry. ~Matthew matthewb@aitech.net AS13746 On Thu, Aug 16, 2018 at 3:25 PM, Frank Bulk <fbulk@mypremieronline.com> wrote: When I force a traceroute to originate from our MICE-facing connection, the first hop is 206.108.255.50 (AS32609 aka CNS). Any reason why? To making things more interesting, Incapsula-destined traffic goes via Paul Bunyan. Here's just one example: traceroute to www.yamaha-dealers.com (45.60.73.16), 30 hops max, 60 byte packets 1 AS32609.micemn.net (206.108.255.50) 14.059 ms 14.084 ms 14.076 ms 2 cns70.cnsllc.net (205.149.150.9) 18.484 ms 18.434 ms 18.507 ms 3 fg30.ips.cnsllc.net (205.149.150.30) 20.254 ms 20.346 ms 20.267 ms 4 crss2.PaulBunyan.net (205.149.159.197) 20.527 ms 20.562 ms 20.619 ms 5 cra.PaulBunyan.net (205.149.159.181) 23.398 ms fp233.ips.PaulBunyan.net (205.149.159.233) 22.669 ms cra.PaulBunyan.net (205.149.159.181) 23.393 ms 6 * * * 7 * * * 8 * * * 9 * * * 10 * * * 11 * * * 12 * * * 13 * * * 14 * * * 15 * * * 16 * * * 17 * * * 18 * * * 19 * * * 20 * * * 21 * * * 22 * * * 23 * * * 24 * * * 25 * * * 26 * * * 27 * * * 28 * * * 29 * * * 30 * * * SiouxCenter-Arista-North(s1) The reason I stumbled across this is because we've had more than a dozen customers over the last month complain about access to Incapsula-protected sites. Packet captures show TCP RSTs coming from the far side. Regards, Frank Bulk AS53347 To unsubscribe from the MICE-DISCUSS list, click the following link: http://lists.iphouse.net/cgi-bin/wa?SUBED1=MICE-DISCUSS&A=1