User Tools

Site Tools


radio:db0fhn:tcpip:routing

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

radio:db0fhn:tcpip:routing [2014/01/12 19:07] (current)
jann created
Line 1: Line 1:
 +The network-44 has been subnetted. You can have a look on the allocation on Brian Kantors "​AMPRNet IP address coordinators"​ list at http://​noh.ucsd.edu/​~brian/​amprnets.txt.
  
 +There'​s a central router at the university of california, san diego announcing the network-44 by BGP. Traffic from the internet will be routed to this central server. Further announcements are unwanted by the network owner Brian Kantor, WB6CYT.
 +
 +To debug routingproblems I double checked whether there are really no other announcements active, but there are. Try telnet://​route-server.belwue.de and type "show ip route 44.0.0.0"​.
 +
 +> route-server>​show ip route 44.0.0.0
 +> Routing entry for 44.0.0.0/8, 3 known subnets
 +>   ​Variably subnetted with 2 masks
 +
 +> B       ​44.0.0.0/​8 [160/0] via 188.1.38.205,​ 01:23:11
 +> B       ​44.16.15.0/​24 [160/0] via 188.1.38.205,​ 2w2d
 +> B       ​44.130.99.0/​24 [160/0] via 80.81.192.74,​ 2w2d
 +
 +The border router will tunnel incoming packages with IP-ENCAP protocol 4 (/​etc/​protocols) to corresponding gateways. There is some documentation how gateways can take part: http://​www.ampr-gateways.org. Traffic to IP-addresses without DNS-entry is blocked as well as port 135-139, 435 and 1025-1028 (TCP/UDP).
 +
 +You can check current routes by ipencap at the Linux shell of DB0FHN with "cat /​opt/​encap/​encap.txt"​. DB0FHN is the central router for germany 44.130.0.0/​16,​ austria 44.143.0.0/​16,​ switzerland 44.142.0.0/​16,​ france 44.151.0.0/​16 and luxembourg 44.161.0.0/​16.
 +
 +To debug routingproblems I double checked whether there are no other gateways active, but there are:
 +> db0fhn:~# grep 44.130 /​opt/​encap/​encap.txt |grep -v 141.75.245.225
 +> route addprivate 44.130.12/​24 encap 139.13.100.33
 +> route addprivate 44.130.98/​24 encap 193.22.2.254
 +> route addprivate 44.130.99/​24 encap 193.22.2.254
 +> route addprivate 44.130.176.120/​29 encap 213.239.233.155
 +> route addprivate 44.130.177.135/​32 encap 213.239.233.155
 +> route addprivate 44.130.146/​24 encap 87.139.127.97
 +> route addprivate 44.130.18/​24 encap 87.139.127.97
 +> db0fhn:~# grep 44.142 /​opt/​encap/​encap.txt |grep -v 141.75.245.225
 +> db0fhn:~# grep 44.143 /​opt/​encap/​encap.txt |grep -v 141.75.245.225
 +> db0fhn:~# grep 44.151 /​opt/​encap/​encap.txt |grep -v 141.75.245.225
 +> db0fhn:~# grep 44.161 /​opt/​encap/​encap.txt |grep -v 141.75.245.225
 +
 +IP-Routing at DB0FHN is complex but I try to explain it. DB0FHN uses iproute2 for all the routing stuff. There are some rules and tables at DB0FHN:
 +> db0fhn:~# ip rule
 +> 0:      from all lookup 255
 +> 210:    from all lookup funk
 +> 220:    from 44.0.0.0/8 lookup ampr2inet
 +> 230:    from all lookup amprtun
 +> 32766: ​ from all lookup main
 +> 32767: ​ from all lookup default
 +
 +Every table has some entries. DB0FHN-10 runs an patched ax25rtd. ax25rtd will learn IP-hostroutes on incoming AX.25 connections and pass the routes to the kernel. Our ax25rtd writes these routes into the table "​funk"​. Assume the kernel has to route an IP-package: The kernel will start with table 0 to 32767 until it will find a match and route the package. So highest priority have routes learned by ax25rtd. Our border node DB0FHN-0 (Xnet) could do this job also, but at DB0FHN are the developers of ax25-apps and ax25-tools working on this piece of software.
 +
 +> db0fhn:~# ip route show table funk
 +> 44.143.144.160 dev ax0  proto ax25rtd ​ scope link
 +> 44.130.18.200 dev ax0  proto ax25rtd ​ scope link
 +> 44.130.18.203 dev ax0  proto ax25rtd ​ scope link
 +> 44.130.42.3 dev ax0  proto ax25rtd ​ scope link
 +> 44.130.60.180 dev ax0  proto ax25rtd ​ scope link
 +> ...
 +
 +The next table "​ampr2inet"​ will only route packages from the network-44 back to the internet. The border gateway at university of california, san diego doesn'​t support reverse routing. I did find a partner in sweden (Pontus Falk) who can transport IP-packages with source-IP from 44.0.0.0/8 to the internet (I'm source route filtered at the provider). I like to route all packages from 44.0.0.0/8 to NOT 44.0.0.0/8 and this was a bit tricky to add into the table:
 +
 +> db0fhn:~# ip route show table ampr2inet
 +> 45.0.0.0/8 via 130.237.41.44 dev tunl0 onlink
 +> 46.0.0.0/7 via 130.237.41.44 dev tunl0 onlink
 +> 40.0.0.0/6 via 130.237.41.44 dev tunl0 onlink
 +> 32.0.0.0/5 via 130.237.41.44 dev tunl0 onlink
 +> 48.0.0.0/4 via 130.237.41.44 dev tunl0 onlink
 +> 0.0.0.0/3 via 130.237.41.44 dev tunl0 onlink
 +> 64.0.0.0/2 via 130.237.41.44 dev tunl0 onlink
 +> 128.0.0.0/1 via 130.237.41.44 dev tunl0 onlink
 +
 +The next table is filled with IP-ENCAP routes from the gateways-project. Every night this table will be automatically updated using a cronjob. I deleted listed iproutes to 44.130.x.x as I prefer to deliver IP-packages by IP over AX.25 through our AX.25 network. The reason is easy. The ax25rtd will learn host routes to be able to answer incoming packages, but I don't have a routing daemon on the tunneling interface running which could do this job. This of course could be improved.
 +
 +> db0fhn:~# ip route show table amprtun
 +> 44.131.94.240 via 82.33.62.185 dev tunl0 onlink
 +> 44.4.28.50 via 66.134.69.212 dev tunl0 onlink
 +> 44.131.93.240 via 82.33.62.185 dev tunl0 onlink
 +> 44.134.208.241 via 146.48.126.28 dev tunl0 onlink
 +> 44.135.96.17 via 132.213.22.244 dev tunl0 onlink
 +> 44.4.92.50 via 66.134.69.212 dev tunl0 onlink
 +> ...
 +
 +DB0FHN is connected to the european rf radio network and its central IGATE-server. We do have the route for 44.0.0.0/8 via 44.130.254.254 in the default table which will be routed by IP over AX.25 to IGATE. IGATE is a patched Xnet AX.25 router (see IGATE-project on mainpage) which supports IP over AX.25. Users will be able to use IGATE as their default IP-router as described at "​Basics with Windows and PC/​Flexnet"​.
radio/db0fhn/tcpip/routing.txt ยท Last modified: 2014/01/12 19:07 by jann