on 15-Oct-2019 02:50
This is more of a what to look for when troubleshooting guide than a step-by-step guide as I believe that troubleshooting is not an exact science..
Here's a rough road map of what we need to know and what I'm gonna show you in this article:
OSPF is a routing protocol that roughly tells each router in the OSPF domain where to send the packet to. If there was no OSPF then we'd have to figure it out by ourselves and configure static routes.
There is much more to it and in order to know more about OSPF I'd recommend this friendly illustrated book: Bryant's advantage ROUTE book.
Apart from that, in order to enable OSPF we need to do it via Route Domain configuration:
And here is how we access the CLI configuration:
Here's where ZebOS/OSPF configuration is stored (per routing domain) because ZebOS is not aware of Routing Domains:
If we had enabled it on Route Domain 1 (for example), then the path would be /config/zebos/rd1 and so on.
K14267 explains what it is and even though the article is about BGP, it also applies for OSPF.
Roughly speaking, RHI allows us to inject a virtual-address into ZebOS' routing table and advertise it into your OSPF/BGP domain and it is very easy to do it.
Here's my routing table when I have no RHI:
Now I use one of my VIPs as example:
Instead of clicking on the VIP itself I go to the virtual-address list:
I picked 10.199.3.143 and enabled Route Advertisement:
PS: Selective is the usual choice but in older versions of BIG-IP we might find only two options (Enabled and Disabled). When this is the case, Enabled behaves like Selective does in newer versions. Please check this AskF5 article about that.
Now look at my routing table and notice that a K route that matches my virtual address magically appeared:
Now we just need to redistribute this route into OSPF with redistribute kernel command similar to what K14267 describes.
We can type this on BIG-IP:
All RHI relevant information should be on /var/tmp/my-box.log. We can even issue tail -f command to follow along in real time.
TMM <-> Network:
TMM <-> Control Plane:
The first packet capture will record the communication externally between BIG-IP and the external device.
The second one will record the communication (internally) between BIG-IP's forwarding plane (tmm) and BIG-IP's control plane daemon responsible to process the routes and install in routing table.
The above commands will print debug information about OSPF networking as well as control plane.