What is the local routing table used for?
First of all as some available on internet info explains "The local table is a special routing table maintained by the kernel".
If you feeling really brave today you can even get some bits of information locally, here's how:
man ip
-- since that was the command you've been tinkering with it makes sense to expect its manual should have some hints on the matter. You should clearly observe now there're so-called SEE ALSO section. Let's look into it attentively -- among other things it shamelessly mentions 2 possible candidates for further inquiry in regards:
ip-route(8)
ip-rule(8)
All in all we have now somewhat:
man 8 ip-route
's:
local
- the destinations are assigned to this host. The packets are looped back and delivered locally.
…
Actually, one other table always exists, which is invisible but even more important. It is the
local
table (ID 255
). This table consists of routes for local and broadcast addresses. The kernel maintains this table automatically and the administrator usually need not modify it or even look at it.
man 8 ip-rule
's:
At startup time the kernel configures the default RPDB consisting of three rules:
- Priority: 0, Selector: match anything, Action: lookup routing table
local
(ID 255
). Thelocal
table is a special routing table containing high priority control routes for local and broadcast addresses.
I personally feel satisfied with the info some authors put into cited manuals but if you're still hungry I guess now you know how to fish.