Skip to content

Instantly share code, notes, and snippets.

@scyto

scyto/.ospf-mesh-net.md

Last active February 22, 2024 18:30
Show Gist options
  • Save scyto/629c61d36af07b5ee45adfb172e25384 to your computer and use it in GitHub Desktop.
Save scyto/629c61d36af07b5ee45adfb172e25384 to your computer and use it in GitHub Desktop.
Download ZIP
IPv4 ospf mesh network for ceph
Raw
.ospf-mesh-net.md

Enable OSPF Routing on Thunderbolt Mesh

This has been deprectaed

It is now superceded by Openfabric Routing see here

continue at your own peril, for reference only now.

Old Gist

This will result in an IPv4 routable mesh network that can survive any one node failure or any one cable failure. All the steps in this section must be performed on each node

Please note the main section of this gist describes IPv4 on mesh. Lower down you will find additonal files that cpatures:

  1. differences if you want dual stack IPv4 / IPv6 routing (this is now what i run since writing the original gist)
  2. opernfabric instead of OSPF (to do)

this gist is part of this series

Key Parameters

Key Information Used Note i used the 10.x IPv4 space as this is not used anywhere else on my network YMMV

lo = loopback en05/06 - these are the thunderbolt ports

Node l:

  • lo:0 = 10.0.0.81/32
  • en05 = 10.0.0.5/30
  • en06 = 10.0.0.9/30
  • ospf router-id = 0.0.0.1

Node 2:

  • lo:0 = 10.0.0.82/32
  • en05 = 10.0.0.10/30
  • en06 = 10.0.0.13/30
  • ospf router-id = 0.0.0.2

Node 3:

  • lo:0 = 10.0.0.83/32
  • en05 = 10.0.0.14/30
  • en06 = 10.0.0.6/30
  • ospf router-id = 0.0.0.3

Enable IPv4 forwarding

Using IPv4 to take advantage of not needing to use addresses - does make things simpler

  • uncomment #net.ipv4.ip_forward=1 using nano /etc/sysctl.conf (remove the # symbol and save the file)

Create Loopback interface

doing this means we don't have to give each thunderbolt a manual IPv6 addrees and that these addresses stay constant no matter what Add the following to each node using nano /etc/network/interfaces

This should go uder the auto lo section and for each node the X should be 1, 2 or depending on the node

auto lo:0
iface lo:0 inet static
        address 10.0.0.8X/32

so on the first node it would look comething like this:

...
auto lo
iface lo inet loopback
 
auto lo:0
iface lo:0 inet static
        address 10.0.0.81/32
...

Save file.

Assign IP address to en05 and en06 using the GUI

  1. use the table further up and assign addresses
  2. after appliying both addresss remeber to hit apply configuration button

Install OSPF (perform on all nodes)

  1. Install Free Range Routing (FRR) apt install frr
  2. Edit the FRR config file: nano /etc/frr/daemons
  3. Adjust ospfd=no to ospfd=yes
  4. save the file
  5. restart the service with systemctl restart frr

Configure OSPF (perforn on all nodes)

  1. enter the FRR shell with vtysh
  2. optionally show the current config with show running-config
  3. enter the configure mode with configure
  4. Apply the bellow configuration (it is possible to cut and paste this into the shell instead of typing it manually, you may need to press return to set the last !. Also check there were no errors in repsonse to the paste text.). Note: the X should be the number of the node you are working on, so for my stetup this would 0.0.0.1, 0.0.0.2 or 0.0.0.3.
ip forwarding
!
router ospf
 ospf router-id 0.0.0.X
 log-adjacency-changes
 exit
!
interface lo
 ip ospf area 0
 exit
!
interface en05
 ip ospf area 0
 ip ospf network broadcast
 exit
!
interface en06
 ip ospf area 0
 ip ospf network broadcast
 exit
!
  1. you may need to pres return after the last ! to get to a new line - if so do this
  2. exit the configure mode with the command end
  3. save the configu with write memory
  4. show the configure applied correctly with show running-config - note the order of the items will be different to how you entered them and thats ok. (If you made a mistake i found the easiest way was to edt /etc/frr/frr.conf - but be careful if you do that.)
  5. use the command exit to leave setup
  6. repeat steps 1 to 9 on the other 3 nodes
  7. once you have configured all 3 nodes issue the command vtysh -c "show ip ospf neighbor" you will see:
root@pve1:~# vtysh -c "show ip ospf neighbor"

Neighbor ID     Pri State           Up Time         Dead Time Address         Interface                        RXmtL RqstL DBsmL
0.0.0.2           1 Full/DROther    52m26s            33.951s 10.0.0.10       en06:10.0.0.9                        0     0     0
0.0.0.3           1 Full/DROther    51m56s            33.444s 10.0.0.6        en05:10.0.0.5                        0     0     0
  1. now issue the command vtysh -c "show ip route" and you will see:
root@pve1:~# vtysh -c "show ip route"
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
       T - Table, v - VNC, V - VNC-Direct, A - Babel, F - PBR,
       f - OpenFabric,
       > - selected route, * - FIB route, q - queued, r - rejected, b - backup
       t - trapped, o - offload failure

C>* 10.0.0.4/30 is directly connected, en05, 00:53:16
O>* 10.0.0.5/32 [110/0] is directly connected, en05, weight 1, 00:53:16
O   10.0.0.6/32 [110/10] via 10.0.0.6, en05 inactive, weight 1, 00:53:11
C>* 10.0.0.8/30 is directly connected, en06, 00:53:46
O>* 10.0.0.9/32 [110/0] is directly connected, en06, weight 1, 00:53:46
O   10.0.0.10/32 [110/10] via 10.0.0.10, en06 inactive, weight 1, 00:53:41
O>* 10.0.0.13/32 [110/10] via 10.0.0.10, en06, weight 1, 00:53:32
O>* 10.0.0.14/32 [110/10] via 10.0.0.6, en05, weight 1, 00:53:11
O   10.0.0.81/32 [110/0] is directly connected, lo, weight 1, 12:15:09
C>* 10.0.0.81/32 is directly connected, lo, 12:15:09
O>* 10.0.0.82/32 [110/10] via 10.0.0.10, en06, weight 1, 00:53:41
O>* 10.0.0.83/32 [110/10] via 10.0.0.6, en05, weight 1, 00:53:11
C>* 192.168.1.0/24 is directly connected, vmbr0, 12:15:06

and lastly ip route

root@pve1:~# ip route
default via 192.168.1.1 dev vmbr0 proto kernel onlink 
10.0.0.4/30 dev en05 proto kernel scope link src 10.0.0.5 
10.0.0.8/30 dev en06 proto kernel scope link src 10.0.0.9 
10.0.0.12/30 nhid 53 proto ospf metric 20 
        nexthop via 10.0.0.6 dev en05 weight 1 
        nexthop via 10.0.0.10 dev en06 weight 1 
10.0.0.82 nhid 54 via 10.0.0.10 dev en06 proto ospf metric 20 
10.0.0.83 nhid 33 via 10.0.0.6 dev en05 proto ospf metric 20 
192.168.1.0/24 dev vmbr0 proto kernel scope link src 192.168.1.81

##Testing Example You can now test the network by pinging the IPv4 loopback addresses of the other nodes. For example ping (using my IPs defined earlier):

  • ping 10.0.0.81
  • ping 10.0.0.82
  • ping 10.0.0.83

Now pull one of the TB cables and repeat the test.

You should still be able to ping all nodes!!

Raw
dual-stack-ospf.md

This supplement is if you want dual stack IPv4 abd IPv6

Note id you are doing CEPH it should be either IPv4 or IPv6 for all the monitors, MDS and daemons - do not try and dual stack it, depite the docs implying it is ok my findsing on quincy are is it is funky.... so stick yp IPv4 or IPv6 - it is possible to switch ceph back and forth - but be very careful.... it will be scary (tl;dr pick one)

Create an IPv6 loopback

In /etc/network/intefaces you will want an IPv6 loopback for IPv6 seperate from IPv4. My best pactice is to use the same number in the last hextet as the last octet from IPv4 - makes things easy to remember)

so PVE1 would look like this, increment the last digit of the IP for each subsequent node.

...
auto lo:6
iface lo:6 inet static
        address fc00::81/128

...

Enable IPv4 and IPv6 forwarding

  1. use nano /etc/sysctl.conf to open the file
  2. uncomment #net.ipv6.conf.all.forwarding=1 (remove the # symbol)
  3. uncomment #net.ipv4.ip_forward=1 (remove the # symbol)
  4. save the file

FRR Setup

This is the content for FRR - rememvber to increment the router-ids on each node you use this on where you see X

edit the frr daemons file to change ospf6d=no to ospf6d=yes and ospfd=no to ospfd=yes

This is the config to issue in vtysh - note if you are moving from a pure IPv4 configu youy might want to stop the serice and delete the frr config file before doing this to reset the config.

ip forwarding
ipv6 forwarding
!
router ospf
 ospf router-id 0.0.0.X
 log-adjacency-changes
 exit
!
router ospf6
 ospf6 router-id 0.0.0.1
 log-adjacency-changes
 timers throttle spf 100 200 5000
 exit
!
interface lo
 ip ospf area 0
 ipv6 ospf6 area 0
 exit
!
interface en05
 ip ospf area 0
 ip ospf network broadcast
 ipv6 ospf6 area 0
 ipv6 ospf6 network broadcast
 exit
!
interface en06
 ip ospf area 0
 ip ospf network broadcast
 ipv6 ospf6 area 0
 ipv6 ospf6 network broadcast
 exit
!

to do: speed up faiover by plaing with deadtime, hello time etc.

@scyto
Copy link
Author

scyto commented Sep 24, 2023

ok, does this seem a more elegant approach? numberless interfaces and simple frr config?

pve3# show running-config 
Building configuration...

Current configuration:
!
frr version 8.5.2
frr defaults traditional
hostname pve3
service integrated-vtysh-config
!
interface en05
 ip router openfabric 1
 ipv6 router openfabric 1
exit
!
interface en06
 ip router openfabric 1
 ipv6 router openfabric 1
exit
!
interface lo
 ip router openfabric 1
 ipv6 router openfabric 1
 openfabric passive
exit
!
router openfabric 1
 net 49.0000.0000.0003.00
exit
!
end

@scyto
Copy link
Author

scyto commented Sep 24, 2023

ok i have now deprecate this gist
it is now replaced with https://gist.github.com/scyto/4c664734535da122f4ab2951b22b2085

@nihr43
Copy link

nihr43 commented Sep 24, 2023

I have no familiarity with openfabric - but if its working go for it.
On slow convergence - frr has a 'datacenter' profile thats supposed to use more aggressive timers. You enable it with frr defaults datacenter at the top of frr.conf. I don't know what its affect will be with openfabric but for me with bgp convergence is pretty much instant.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment