Incoming Packets from 10.x.x.x address

[andrew4728]

Hey all, I wanted to see if you knew whether this sounds normal or not.

I setup an access list on my cisco 2514 to filter out INCOMING traffic from my Cable modem (cox)

One specific entry I put in was :
access-list 100 deny ip 10.0.0.0 0.255.255.255 any log

After putting this into my router and enabling it on ethernet0 to filter INcoming traffic, I started getting :

18:43:20: %SEC-6-IPACCESSLOGP: list 100 denied udp 10.100.160.1(0) -> 255.255.255.255(0), 17 packets

This concerned me, as this deny kept occuring every 5 minutes, pretty much on the dot.

I thought something might be up, until I noticed, any time when I tracert to an address (yahoo.com or my ISPs local DNS server), the Trace goes through 10.100.160.1 every time on the first hop.

My ISPs Tech Support WELL below average, and many of them don't know what tracert is, so I was unable to get a definite answer from them whether this is normal or not.

Does this sound normal, my connections all seem to go through a node using a reserved IP (10.x.x.x) and are routed to external IPs then.

and would anyone know what the udp packets coming to my router every 5 minutes might be?

Thanks!

 

[lui3]

10.100.160.1

is this also your default gateway from dhcp? or is this the next hop after your router. It may be a heartbeat signal used to verify the state of your connection. 0 is normally a ping type echo packet although they are normally icmp not udp. hmm

 

[andrew4728]

My Default gateway is 68.13.x.x
10.100.160.1 is the next hop after my router, on any Tracert I've done so far..