Nighthawk M1 Passthrough Mode (Telstra Model)

[Slaziar]

Hi All,

I have firmware version NTG9X50C_12.06.02.00 that is set up as IP Passthrough to a Cisco ASA-5506-X.

My ASA gets the public IP Address (I have a public IP through Telstra, not CG-NAT), but I couldn't get any traffic to pass through it. After some debugging I found that I'm not getting any arp replies for Telstra's default gateway. Since the M1 intercepts packets instead of doing true unadulterated bridge (since it adds a route for the Netgear default - 192.168.245.254/32, and seems to show the same IP on its interface), is it possible that the M1 isn't sending a proper arp reply? Once I add a static arp entry, traffic passes freely, but of course the arp entry isn't always the same since my IP is still dynamic. I'm happy to attach any logs, packet dumps, etc if required. Update: It looks like the M1 does intercept the arp traffic as the MAC I get in the dhcp reply is the same MAC as the M1.

Secondly I get a constant 350kbps on the interface to the Cisco, and the packet dump reveals the router gets spammed with the following:

NOTIFY * HTTP/1.1
HOST: 239.255.255.250:1900
CACHE-CONTROL: max-age=2
LOCATION: http://192.168.245.254:57917/rootDesc.xml
SERVER: Ubuntu/lucid UPnP/1.1 MiniUPnPd/1.8
NT: upnp:rootdevice
USN: uuid:4e229070-f9a3-4d04-8c36-5cea8b866bec::upnp:rootdevice
NTS: ssdp:alive
OPT: "http://schemas.upnp.org/upnp/1/0/"; ns=01
01-NLS: 1
BOOTID.UPNP.ORG: 1
CONFIGID.UPNP.ORG: 1337

Why would a bridge device want uPnP access? Can you please advise if it's trying to request a vital port forward (why?) or anything - especially at 350Kbps? I have disabled UPnP & DLNA to no effect.

[Slaziar]

Nevermind, UPnP traffic is back (it wasn't for about 5 minutes after boot)

[Slaziar]

Apologies, without change it appears the UPnP packets have stopped.

I've worked out that due to the M1 changing the subnet mask in dhcp from the MNO(Mobile Network Operator), it's creating a 'non-adjacent' network as the ip is for example 123.123.123.123/32 with a gateway of 123.123.123.1. However the MNO are sending a /24 subnet mask. And since they're not on the same network the router rejects any arp replies as 'non-adjacent networks'.