ping and tracert networking question

[Ether]

Need some help from network gurus.

My internet access at home is via WISP.

When it is working properly, I can ping and tracert the tower with very little latency.

Occasionally it will stop working, and I've discovered that when that happens I can ping the tower but tracert does not work (or takes an inordinately long time).

What would be some possible explanations that would fit that set of facts?

[aryker]

This happens on my home network as well. The situation isn't exactly the same, since I don't have a WISP. Instead, I have sort of a LAN within a LAN that I use for testing purposes(I work as a researcher for a distributed systems and security lab). For me, the problem is old wifi hardware that is probably nearing the end of its lifespan, which I am also too lazy to fix until it dies completely

Can you give more information on what hardware you are using? That could be the problem. Also, do you know anyone else who uses the same WISP who may be having similar issues? If that is the case, it's probably an issue on your provider's end, in which case you should contact them and see if they can isolate the issue.

[Ether]

Ubquiti AirOS PowerStation2

[aryker]

Originally Posted by Ether

Ubquiti AirOS PowerStation2

Hmm--unless you bought it used, I doubt that's where the problem is. When it is not working properly, are you still able to navigate to a web page(i.e. make HTTP requests) successfully?

[Ether]

Originally Posted by aryker

When it is not working properly, are you still able to navigate to a web page(i.e. make HTTP requests) successfully?

No. For purposes of this discussion, not being able to access web pages is what I mean by "not working properly".

[aryker]

Originally Posted by Ether

For purposes of this discussion, not being able to access web pages is what I mean by "not working properly".

Just checking

How frequently does this occur? Multiple times per day? Per week? Also, I assume you've taken a look at your PowerStation during these times to make sure nothing was obviously out of place?

[techhelpbb]

How many hops in your traceroute when it is working?
Are you going to a DNS entry or an IP?

[Ether]

Originally Posted by techhelpbb

How many hops in your traceroute when it is working?
Are you going to a DNS entry or an IP?

Even a tracert to an IP 3 hops away doesn't work (or takes forever).

[techhelpbb]

Originally Posted by Ether

Even a tracert to an IP 3 hops away doesn't work (or takes forever).

Trying to figure out if you are pinging your local gateway which will work even without the tower but tracerouting to a website which times out over ICMP because the tower is not connected (you can traceroute over UDP as well). That is why I asked how many hops when you are working I assumed you tracerouted to a fixed place in the network before the Internet.

[Ether]

Originally Posted by techhelpbb

That is why I asked how many hops when you are working

I thought I answered that:

Originally Posted by Ether

a tracert to an IP 3 hops away

Maybe I'm not understanding what you're asking.

[techhelpbb]

Originally Posted by Ether

I thought I answered that:

The IP 3 hops away is probably at the network level near that ISP's perimeter.
So if the DNS doesn't turn out to be the issue you probably have lost your connection to them over that link.

If you have the information to access the equipment on your side you can probably query the status of the connectivity to the tower from the web interface. I think that unit supports SNMP as well so you could query the status of the link from that. They appear to have an MIB for that purpose available. Then you could work it out such that you can monitor the signal level and data transmission rates.

[Jared Russell]

It could be DNS resolution. Most implementations of tracert will attempt to resolve each IP along the way, and this can take a long time with a flaky DNS server.

A couple suggestions:

a) Try running tracert with the -d flag (Windows) or -n (Linux).

b) Try using an open DNS service, like OpenDNS (208.67.222.222/208.67.222.220) or Google Public DNS (8.8.8.8/8.8.4.4).

[Ether]

Originally Posted by Jared341

It could be DNS resolution. Most implementations of tracert will attempt to resolve each IP along the way...

OK, this is where I have some confusion. I thought DNS was to resolve a name into an IP address. Why is DNS required if I am already providing the IP address?

A couple suggestions:

a) Try running tracert with the -d flag.

b) Try using an open DNS service, like OpenDNS (208.67.222.222/208.67.222.220) or Google Public DNS (8.8.8.8/8.8.4.4).

Thanks. I will try that next time it misbehaves.

[Jared Russell]

Originally Posted by Ether

OK, this is where I have some confusion. I thought DNS was to resolve a name into an IP address. Why is DNS required if I am already providing the IP address?]

By default, tracert will still use DNS to try to look up a name for each hop so it can display it as part of the output. Use "-d" (Windows) or "-n" (Linux) to tell it to skip that part.

[Ether]

Originally Posted by aryker

Just checking

How frequently does this occur? Multiple times per day? Per week?

Couple of times a week. Random.

Actually, it has a Murphy sensor. Its happens at the worst possible times. Like when I'm about to submit my tax return, or in the middle of a purchase or a bank transaction.

Also, I assume you've taken a look at your PowerStation during these times to make sure nothing was obviously out of place?

It's on the roof (2 stories). At night I can sort of see the signal strength LEDs with binoculars.