Internet connection

[alb000001]

Issue with Internet, currently using a Cisco router 881W to connect to WAN. Have limited to no internet for a week now. Router connected to Spectrum Cable modem.  Have a pack of 5 Static IP addresses from Spectrum. We have had no issues for +3 years with current setup and config.  As of last week we have an issue. When run ping internally to 8.8.8.8 get high latency or timed out.  Router shows no packet loss or cpu issue, have swapped out with another Cisco C1111 Router, same config, same issue, have checked stats on internal switch, no issue, have swapped out to make sure, have run MTR software, shows packet loss after cable modem outside of network. ping test on switch shows no issue to router interface, shows packet loss to modem interface. Tracrt shows high latency and packet loss after cable modem outside.

[johnd2310]

Hi ,

Have you tried swapping out the cable modem?

Thanks

John

[alb000001]

Yes, the original plus 2 new ones, same thing.

[Giuseppe Larosa]

Hello,

having changed both the internal Cisco router and the cable modem with no changes, it is high time to open a ticket with the cable modem internet service provider.

The issue is likely in their access network.

Hope to help

Giuseppe

[Georg Pauwen]

Hello,

on a side note, make sure it is not an MTU issue. From one of the workstations, send a ping with the 'don't fragment bit' set, and with different packet sizes, until you get a valid reply:

C:\Users\pauwe>ping -l 1474 -f 8.8.8.8

Pinging 8.8.8.8 with 1474 bytes of data:
Packet needs to be fragmented but DF set. <-- reply not valid
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.

Ping statistics for 8.8.8.8:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

C:\Users\pauwe>ping -l 1472 -f 8.8.8.8

Pinging 8.8.8.8 with 1472 bytes of data:
Reply from 8.8.8.8: bytes=68 (sent 1472) time=11ms TTL=55 <-- valid reply
Reply from 8.8.8.8: bytes=68 (sent 1472) time=11ms TTL=55
Reply from 8.8.8.8: bytes=68 (sent 1472) time=10ms TTL=55
Reply from 8.8.8.8: bytes=68 (sent 1472) time=11ms TTL=55

Ping statistics for 8.8.8.8:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 10ms, Maximum = 11ms, Average = 10ms

On your outgoing interface, try and set the MTU to something low like 1400 (and the tcp adjust-mss to 1360), and check if that makes a difference.