This is an old revision of the document!
Most of the vantage points are now ipv4 default, so:
show bgp ipv4 unicast 203.190.181.0 ! to pull a route sh ip bgp regexp _200981$ ! regexp anything from our ASN sh ip bgp regexp _200981$ ! regexp anything from our ASN show bgp ipv4 unicast regexp 174_([0-9]+)_200981$ ! regexp anything from our ASN traversing Cogent
FRR routing FREE RANGE ROUTING
http://docs.frrouting.org/en/latest/bgp.html
Zebra IS THE RIB
To restart frr:
/usr/lib/frr/frr-reload.py /etc/frr/frr.conf --reload /usr/lib/frr/frrinit.sh restart
Also here: https://github.com/FRRouting/frr/blob/master/tools/frr-reload.py
Binding files: External Link,
Route Servers IXP:
FLOWSPEC NOTES RFC 5575
To filter (apply actions) on flows instead of penalising whole prefix ranges.
Actions to be done are transmitted via a BGP session from the controller (tells the router what to filter).SAFI 133.
More specifically, actions are encoded in EXT-COMMUNITIES
- We use exabgp to send and receive flowspec messages over the bgp connection
- In this articlewe can see how we do : flowspec-bgp-msg > acl > iptable rules
- however it gives for granted that we know how to generate and send flowspec messages.
- the message was sent by sFlow-RT/exabgp. More info here
- flowspec and containerlab: External Link
Flowspec in junos:
> show route table inetflow.0 extensive inetflow.0: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden) 4.4.4.4,*,proto=17,srcport=53,len>=450&<=600/term:1 (1 entry, 1 announced) TSI: KRT in dfwd; Action(s): discard,count Page 0 idx 0, (group ArborSP type Internal) Type 1 val a3be258 (adv_entry) Advertised metrics: Nexthop: Self Localpref: 100 AS path: [65530] ? Communities: 65530:100 65530:134 no-export traffic-rate:0:0 Cluster ID: 192.168.252.12 Originator ID: 10.2.25.68 Advertise: 000006f7 Path 4.4.4.4,*,proto=17,srcport=53,len>=450&
EXABGP NOTES:
exabgp api accepts these commands which can be entered either via python swriting stdio (exabgp listents it) or directly via exabgpcli.
Ways to start exabgp:
sudo env exabgp.daemon.user=root exabgp-4.0.0/sbin/exabgp exabgp.conf sudo env exabgp.debug.configuration=1 exabgp.debug.pdb=1 exabgp.daemon.user=root exabgp-4.0.0/sbin/exabgp exabgp.conf exabgp ./exabgp.conf
Links:
Examples of flowspec messages. They follow Juniper style
'announce route 100.10.0.0/24 next-hop self',
'announce route 200.20.0.0/24 next-hop self',
'announce flow route { match { destination 172.16.0.0/24; } then { discard; } }',
DDOS protection with RTBH and flowspec:
External_Link
Anycast can also be used to prevent inter-regios ddos (Cloudflare):
