[clug] Next CLUG meeting - May 25th 2017 - Traceroute and false diagnoses on networks

[Bob Edwards]

Thanks for all the helpful homework, Seamus - I am definitely looking
forward to your presentation.

A heads-up for others that this talk is likely to be heavily networking
oriented and not specifically about anything Linuxy. The tools are all
open-source and the protocols all open, so worth celebrating from a
Linux/FOSS point of view.

As with all the CLUG talks, some "Linux Users" (LU in CLUG) will
likely get a lot out of this but others may find it not so relevant
or not targetted specifically at their level. YMMV, as they say.

cheers,

Bob Edwards.

On 11/05/17 23:50, Seamus Murray via linux wrote:
> Conventions and Terms Used in the Presentation...
>
> The "traceroute" term is used as:
> - the name of the software tool, e.g. “use traceroute to test the connectivity from Host-W to Host-E”
> - the action of running the tool, e.g. “run a traceroute from Host-W to Host-E”
> - the results from running the tool, e.g. “look at the traceroute to help diagnose the issue”
>
> To keep things simple, I have only drawn a single IP address in the illustrations of the routers. In the real world, a router would have at least two IP addresses.
>
> The network addresses are written using CIDR notation (Classless Inter-Domain Routing), e.g.:
> - 10.10.0.0/24 is the network range from 10.10.0.0 to 10.10.0.255;
> - 192.168.0.0/24 is the network range from 192.168.0.0 to 192.168.0.255.
>
> The term "node" refers to any devices capable of receiving or sending TCP traffic, such as compute host, router, firewall etc…
>
> The terms "route" and "path" are interchangeable.
>
> The terms "routing" and "forwarding" are similar, but vary slightly terms of magnitude:
> - "forwarding" refers to sending a packet one hop towards a destination;
> - "routing" refers to sending a packet towards its destination (via one or more hops).
>
> The Term "ICMP Time Exceeded" is used in place of the full term "ICMP, Time-to-Live exceeded (Type 11), TTL equal 0 during transit (Code 0)"
>
>
>
> Links...
>
> https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol
> https://en.wikipedia.org/wiki/Traceroute
> https://en.wikipedia.org/wiki/Internet_Protocol
> https://en.wikipedia.org/wiki/Transmission_Control_Protocol
> https://en.wikipedia.org/wiki/Time_to_live
> https://en.wikipedia.org/wiki/Ping_(networking_utility)
> https://en.wikipedia.org/wiki/Van_Jacobson
> https://tools.ietf.org/html/rfc1918
> https://tools.ietf.org/html/rfc792
>
>
>
> Cheers
> Seamus Murray
>
>       From: Bryan Kilgallin (iiNet) via linux <linux at lists.samba.org>
>  To: linux at lists.samba.org
>  Sent: Tuesday, 9 May 2017, 23:26
>  Subject: Re: [clug] Next CLUG meeting - May 25th 2017 - Traceroute and false diagnoses on networks
>
> Thanks, Steven:
>
>> * An animated explanation of how the packet loss and latency displayed
>> in the output of traceroute can cause you to make a false diagnosis.
>
> Seamus, I would like a reminder on the technical terms.
>
>> * Series of diagrams and animations that illustrate each of the topics
>> mentioned above.
>
> I'd like a link to these posted here.
>