This is, most probably, link aggregation interface 2 on a router named br1 in the Telehouse North data centre in London, UK. In the above example, you will see .net.uk. Many large providers put information about their routers in the DNS name. The DNS names shown by MTR can be very revealing. Or it might just mean that none of the last few hops send TTL time exceeded messages. If all of the ? hosts are at the end, then this might be indicative of a problem (that is, 100% packet loss from that point). The trace got beyond that hop, so it’s not a problem. This isn’t uncommon and is nothing to worry about if the missing hops are in the middle of the trace. That is because it did not send a TTL time exceeded message in response to our probe. In the above MTR, you will see eight hops. The average, best, worst and standard deviation round trip times, since you started running the MTR.The round trip time (that is, how long it took to get a response) for the hop.The percentage of packets lost by that hop.
The hostname or IP address of that particular hop on the network (run mtr -n if you don’t want it to resolve IPs to hostname).
Keys: Help Display mode Restart statistics Order of fields quitġ. Output from the MTR command looks something like the following: My traceroute ICMP is usually the default for MTR so no parameters are needed. For traceroute you should call it traceroute -I for ICMP mode. In this author’s experience, ICMP is a more reliable type of trace so should be your first port of call. Some routers will not send TTL time exceeded messages for UDP, ICMP, or both. We use the source IP address and timings of the TTL time exceeded messages to build our path list. We then send a packet with a TTL of 2 and it is rejected at the second router in the network, and so on. The idea is that if a packet is sent with a TTL of 1, it will be rejected (with a TTL time exceeded ICMP message) at the first router in the network.
#MTR REPORT SERIES#
The two main types are User Datagram Protocol (UDP) and Internet Control Message Protocol (ICMP).īoth trace types send a series of packets, with incrementing Time to Live (TTL) fields. Traceroute and MTR both support different types of tracing. In this post, we’ll talk in the context of the output of MTR given it is more versatile. If you want to diagnose a problem such as packet loss, MTR is the tool to use. If you simply want to find the routers your packet passes through, a traceroute is fine. Traceroute is a one-shot sort of tool, whereas MTR runs and aggregates the results of several traceroutes. The traceroute and My Traceroute (MTR) tools can be used to identify the routers a packet passes through between you and a given destination IP address. When a packet travels across the Internet, it travels through multiple routers.
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