ICX 7750 routing table confuses me

[clayton_taverni]

We have a 7750 as our core router and remotes sites with either a 7750 or 7450 as their router.  The configurations were set up by an outside vendor and they only answer about half my questions.

The core 7750 has routes something like:

ip route 10.10.0.0/16 ip_address_1
ip route 10.20.0.0/16 ip_address_2
ip route 10.30.0.0/16 ip_address_3
ip route 10.40.0.0/16 ip_address_4
ip route 10.41.0.0/16 ip_address_4

Each site has a wired network (10.10, 10.20, etc) and a wireless network (10.11, 10.21, etc).

My confusion comes from why some of the sites only have the wired route while others have both a wired route and a wireless route but everything works just fine.

As I understood it, having 10.10.0.0/16 as an ip route means that any packet with a 10.10.x.x address gets routed to ip_address_1.  So how do the 10.11.x.x addressed packets end up in the same place?  If I set up a 10.12.0.0 vlan, would it need it's own route?

Any explanation/clarification would be appreciated.

[roberto_hernand]

I would have to understand the entire architecture but sometimes you want specific routes to a static destination and you do not want it to be affected by the dynamic routing. There could be other reasons based on the implementation It is not unusual to have a mix. In theory, dynamic routing is preferred because its dynamic and its easier to maintain across the network. However, I cannot specifically say why in this case it is the way it is as it would require knowledge of the entire network architecture, and purpose to understand why it was designed this way.

[clayton_taverni]

Thanks for taking the time to explain all this to me.

Last question: The section of the dynamic table that I shared is copied (other than the IP addresses) for most but not all of our sites.  So, knowing what little you know about our infrastructure, could you explain why the dynamic routes wouldn't be copied across all our sites?  In other words, why are some of the sites missing most of the dynamic routes if the vlans are defined on all our switches?

[roberto_hernand]

That would be difficult to know. What I can tell you is that knowing that you are running OSPF, it should replicate across as OSPF (LSDB) database is replicated. However, there are feature in OSPF that may filter, or summarized routes, or not allow certain routes to be propagated. Also if the greater network (at the core) uses routing protocol, like BGP or ISIS then there could be further filtering of routes. My guess is that some of the sites may just have default routes since they may not have more paths than one (typically known as stubby areas in OSPF)

[clayton_taverni]

Thanks again for taking the time.