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Mention simple example:
It is extremely easy for a Network Operator of a particular AS to find out if and
how another AS can be reached. All he has to do, is to look at the current routing
table for the path from his AS to the target AS. This would be sufficient for
one-way communication, but in practice, most communication is two-way and
there is no-way for the network operator to tell if the target AS has route
back to source-AS. Historical information is also essential when trying to
debug problems that only show up now and again. Specifically, the routing
table doesn’t indicate when a route was last announced or withdrawn.
Default-free routing table contains
routes to all globally known networks. This means that a default-free router,
i.e. Internet Backbone Router, actively decides where to send packets with a
destination outside the AS to which the router belongs, and not forward it, by
default, to another router.
By default, EBGP TTL=1, peers are
directly connected. By default, Multi-hop EBGP, TTL=255, peer NOT directly
connected. Curiosa: IBGP TTL=255, because IBGP peers are usually NOT directly
connected. Sun Enterprise 420 database server called Abcoude.
Blablabla
Running dbinsert on RRC00 (sql over
network) not a problem – plenty of bandwidth
MRT software includes multi-protocol
IPv4/IPv6 routing daemons and routing analysis/simulation tools. Hecate –
RRC00, Iris – RRC01, Pag – RRC02, Cres – RRC03, Vis – RRC04, Dugi – RRC05,
Susak – RRC06
ASInuse – Last time certain AS was seen on the Internet
Search by AS – All prefixes seen originating from specified AS.
Search by prefix – Prefix and associated AS paths seen by RIS (originating AS’s)
Looking
Glasses
– At seven locations: RIPE NCC,
LINX, SFINX, AMS-IX, CIXP, VIX, NSPIXP2
Show IP BGP displays the BGP
table. In our case, the BGP table entry for a particular network because of
hardware performance restrictions.
Show IP BGP summary displays a summary of the entire BGP table.
Raw data - Data only stored in MySQL for 3 months, Raw Data since the beginning
of the project.
Ris-report plots statistics based on RIS data (currently
up to 24 hours lag, working on 1-2 hours lag)
AS702 – UUnet Europe
Click on link – 158.116.242.0/23
interested me
Both 158.116.0.0/16 and 158.116.242.0/23
seen by ris (Probably IGP and DDR or something as backup between Corp HQ and
office in Europe)
Best route -> loc pref same, consider
shortest AS path (3 as hops), best MED (10)
Best route 2 -> loc pref
and aspath same (2 AS-hops) , no med, trust oldest route
AS2914 – Verio
INC, owned by Japanese NTT Communications
(Verio has own class B: 129.250.0.0/16)
Netname: SOLECTRON
Netblock: 158.116.0.0 -
158.116.255.255
Old class B address space (AS18882) – PI space 158.116.242.0/23 assigned to remote
office in Ireland, announced by AS702 (Alder.net) – UK & Ireland, AS701(UUnet)
– US, 18882 single-homed AS peering with AS701.
How RRC00 sees the announcement of
Solectron’s IP address space
MRTG – Multi RouterTraffic Grapher (Plots routing information)
The Multi Router Traffic Grapher (MRTG) is a tool to monitor the traffic load on
network-links. MRTG generates HTML pages containing GIF images which provide a
LIVE visual representation of this traffic.
GNUplot: Histograms, Pie-charts that RRD
cannot do.
Five RRD dBases per RRC. Implemented on
RRC00 and RRC01. Explain a bit about Thomas Franchetti’s SQL2RRD and new
implementation of it .RRD is dbase. What is .s2r? They contain the SQL
statement used for data inserted into RRD. Perl scripts use RRDTool to plot
graphs. New implementation: New program developed by Softies that will insert
data into RRD directly from binary format. Improves performance because
querying dBase is eliminated. Idea is using this process for time-sensitive
data, eg count, withdrawals etc. SQL2RRD will probably still be implemented
for experimental purposes or less time-sensitive stuff, e.g. AS path length statistics,
AS’s or Prefixes seen, ratios allocated/ annouced etc, that might be easier to
derive for SQL before inserting into RRD. Dead parts in graphs – 1. Their box,
Our box, dbinsert (data missing in MySQL 4. Sql2rrd problems (RRD cannot go
back in time to fix ‘no data spots’).
Usually some instabilities due to
reboots, policy changes, physical / data-link layer problems etc (also
pathological updates). Most networks are reachable but high levels of update
activity can kill router’s CPU and Mem
BGP message storms – high activity
kills keep-alives which kills the BGP sessions – withdrawals propagate
through-out the Internet – end-user experiences slow or no performance –
solution: higher IP precedence for BGP keepalives – router still services
keepalives even though congested