RE: Routing Table Question

From: "Thor \(Hammer of God\)" <thor@xxxxxxxxxxxxxxx>
To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx>
Date: Fri, 20 Jan 2006 15:41:49 -0800

You said "As a rule of thumb; you want to populate your routes using RRAS if its installed." But if you did that- if you used RRAS routing entries, ISA would most certainly "depend" on the RRAS service to get that routing information.

i.e. Local net is 192.168.1.0. Another network, 192.168.2.0 is reached via a router- say, 192.168.1.254. If you used RRAS on ISA to create a route to 192.168.2.0 via 192.168.1.254, and the RRAS service failed, the ISA box would no longer know how to get to 192.168.2.0. If you used "route -p add 192.168.2.0 mask 255.255.255.0 192.168.1.254" instead, then it would. That's my point. Don't use RRAS entries to tell ISA about networks ISA needs to know about.

-----
"I'll see your Llama and up you a Badger."
John T

----- Original Message ----- From: "Jim Harrison" <Jim@xxxxxxxxxxxx> To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx> Sent: Friday, January 20, 2006 3:26 PM Subject: [isalist] RE: Routing Table Question


http://www.ISAserver.org

ISA doesn't "depend on" RRAS for local net routing, but it does know how to gather data from it.


-------------------------------------------------------
  Jim Harrison
  MCP(NT4, W2K), A+, Network+, PCG
  http://isaserver.org/Jim_Harrison/
  http://isatools.org
  Read the help / books / articles!
-------------------------------------------------------


-----Original Message-----
From: Thor (Hammer of God) [mailto:thor@xxxxxxxxxxxxxxx]
Sent: Friday, January 20, 2006 15:20
To: [ISAserver.org Discussion List]
Subject: [isalist] RE: Routing Table Question

http://www.ISAserver.org


Of course- that's its purpose...

2 caveats, though. One, if RRAS is installed on the box before you install ISA, and you have a static route to other networks in RRAS, ISA won't take that network and automatically add it to its list of IP's for the internal network. It will, however, take a system route added with "route add" and add the destination network to it's Internal list. My guess is that you wrote it like that on purpose as the stack is more authoritative for "local" traffic.

Two, while I agree that in normal RRAS situations you should use the RRAS interface to manage your routing, when it comes to RRAS on ISA, ISA should *not* have to depend upon the RRAS service for it's own routing needs. Remote Access might go down, but internal routing to other subnets will continue to work properly if the routes are added directly to the system rather than RRAS.

-----
"I'll see your Llama and up you a Badger."
John T

----- Original Message -----
From: "Jim Harrison" <Jim@xxxxxxxxxxxx>
To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx>
Sent: Friday, January 20, 2006 2:55 PM
Subject: [isalist] RE: Routing Table Question


http://www.ISAserver.org

I misspoke..

RRAS can carry routes that do not appear in the system routing table.
ISA doesn't care where the routes are; it "merges" them.

-------------------------------------------------------
  Jim Harrison
  MCP(NT4, W2K), A+, Network+, PCG
  http://isaserver.org/Jim_Harrison/
  http://isatools.org
  Read the help / books / articles!
-------------------------------------------------------


-----Original Message-----
From: Thor (Hammer of God) [mailto:thor@xxxxxxxxxxxxxxx]
Sent: Friday, January 20, 2006 13:37
To: [ISAserver.org Discussion List]
Subject: [isalist] RE: Routing Table Question

http://www.ISAserver.org

RRAS doesn't write to the system routes - just its "own" routes.  If I
create a static route with "route -p add" RRAS will see it and use it, but
RRAS cannot delete it.

When it comes to ISA routes (for ISA itself, as in a complex network), I
*always* use system routes and not RRAS.  I assume this is one of the
excpetions you note, yes?

-----
"I'll see your Llama and up you a Badger."
John T

----- Original Message -----
From: "Jim Harrison" <Jim@xxxxxxxxxxxx>
To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx>
Sent: Friday, January 20, 2006 1:29 PM
Subject: [isalist] RE: Routing Table Question


http://www.ISAserver.org

Actually it reads and writes.
As a rule of thumb; you want to populate your routes using RRAS if its
installed.
There are exceptions to this, but they're few and far between...

-------------------------------------------------------
  Jim Harrison
  MCP(NT4, W2K), A+, Network+, PCG
  http://isaserver.org/Jim_Harrison/
  http://isatools.org
  Read the help / books / articles!
-------------------------------------------------------

RE: Routing Table Question

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