Iptables – How to reload default Mac OSX routing table without rebooting

eth0iptablesmac-osxnetworkingrouting

Greetings,

I'm using vpnc for a VPN client. I'm also doing some tricky things with route to make sure I can still access my local network, etc. etc. (the particulars here are not very important).

Sometimes I get the routing table so jacked up I get ping: sendto: Network is unreachable for urls that should otherwise resolve.

Currently, if I restart Mac OS X then everything is back to normal. What I'd like to do is reset the routing tables to the "default" (e.g. what it is set to at boot) without a whole system reboot.

I think that step 1 is route flush (to remove all routes). And step 2 needs to reload all of the default routes.

Any thoughts on how to do this? (e.g. what is step 2?)

EDIT
Also, I'm noticing another symptom is traceroute also fails on the address in question. For instance:

traceroute the.good.dns.name

traceroute: bind: Can't assign requested address

Best Answer

You need to flush the routes . Use route -n flush several times . Afterwards add your routes with route add.

Related Solutions

Linux – Automatically updating routing table on server

Configure a dynamic routing protocol on all of the routers and configure the servers (and any other hosts) to use the "main" router as their DG. The DG should then handle redirecting traffic to the appropriate router based on entries in the dynamic routing table.

It's not an extra hop in the sense that the traffic destined for one of the other networks won't be forwarded through the default gateway to that network. If I'm not mistaken, the default gateway should issue an ICMP redirect to the host, directing the host to the preferred gateway for the network in question. The only time the default gateway will forward traffic is when it doesn't have a route for the network in question (an external network), in which case it will forward it to it's default gateway.

My comment is based on the assumption that all of the routers have an interface connected to the same LAN subnet (as implied in your question).

How do policy based routing tables actually work

Actually, I think the confusion comes from the fact that those instructions are mixing two topics :

Dealing with policy routing
Setting up your standard routing table in a best-practice way

These three lines

    ip route add $P1_NET dev $IF1 src $IP1
    ip route add $P2_NET dev $IF2 src $IP2
    ip route add default via $P1

are there to handle traffic that doesn't get matched by your policy routes for whatever reason (you add a loopback on the router for example, and use it for management). They are not strictly necessary for the PBR to work, but it's best to have them there all the same.

Best Answer

Related Solutions

Linux – Automatically updating routing table on server

How do policy based routing tables actually work

Related Topic