Understanding a TRACEROUTE

General Support > Basic Network Tests
Understanding a traceroute is relatively simple.   Here's a traceroute from a PC in our office to a server on the internet..

Tracing route to network-online.co.uk [] over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms cbs2.networkonline.local []
2 2 ms <1 ms <1 ms
3 45 ms 46 ms 46 ms lo0-central1.pcl-ag02.plus.net []
4 47 ms 48 ms 44 ms gi1-13-211.pcl-gw01.plus.net []
5 45 ms 45 ms 45 ms te2-1.pcl-gw02.plus.net []
6 45 ms 46 ms 45 ms te2-2.thn-gw2.plus.net []
7 45 ms 46 ms 45 ms xe-1-1-0-0.lon10.ip4.tinet.net []
8 45 ms 45 ms 45 ms gw.ip4.tinet.net []
9 58 ms 57 ms 56 ms
10 58 ms 57 ms 58 ms core-01.net.uk []
11 44 ms 45 ms 44 ms []

Step 1 - this a connection to a server in our office that controls all outgoing connections from our office network
Step 2 - the connection reaches our router after passing through a hardware firewall router (invisible on this network)
Step 3 to Step 6 - the connection is now with our ISP.  It travels through various routers at our ISP before hitting the "internet proper" in London
Step 7 and 8 - the connection is travelling along a connection from tinet.net for a couple of hops
Step 9 - it reaches the outer core of our network in London
Step 10 - the connection is routed from London to Edinburgh and arrives at a core router in Edinburgh
Step 11 - after passing through our hardware firewall and switches (invisible to the traceroute) it arrives at the server our site is located on.

Although this traceroute is very simple, it does show that a connection between your computer and an online service passes through a lot of different hardware and networks before a connection is completed. Connection problems can occur at any point along this network which is why a carrying out a traceroute is extremely important if you are having problems connecting to an online service.

Just because connections to some sites works, doesn't mean the connection to another site will be OK.  Only a traceroute can provide the information necessary to make an informed decision about where the problems with a connection lies.