Dave

Ideally questions regarding Communications Server, both the IP and SNA 
components, should be posed in the IBMTCP-L list:

For IBMTCP-L subscribe / signoff / archive access instructions, send email to 
[email protected] with the message: INFO IBMTCP-L

However, since I'm here, I'll have a shot at providing an answer.

> I believe that static routes are always preferred over dynamic routes ...

No.

You need to become familiar with the description of the (NO)REPLACEABLE 
parameter of the ROUTE statement which, since it's not too much, the text of 
which follows:

<quote>

REPLACEABLE | NOREPLACEABLE

Indicates whether or not the static route can be replaced by OMPROUTE and 
router advertisements when a dynamic route to the same destination is 
discovered.

NOREPLACEABLE

Indicates that static routes cannot be replaced by dynamic routes. The static 
route is always used to reach the destination, regardless of when dynamic 
routes are available. This is the default setting. This parameter can be 
abbreviated as NOREPL. 

REPLACEABLE

Indicates that the static route can be replaced by OMPROUTE and router 
advertisements when a dynamic route to the same destination is discovered. This 
parameter can be abbreviated REPL.

Restrictions:

- Only one type (replaceable or nonreplaceable) of static route can be defined 
to the same destination. All static routes defined to a destination must match 
the type of the first static route defined to that destination. Any definitions 
that do not match that type are rejected.

- Replaceable static routes cannot be defined to destination addresses that 
correspond to dynamic VIPAs for which the TCP/IP stack is a sysplex distributor 
target.

Tip: You can use the Netstat ROUTE/-r RSTAT command to display all replaceable 
static routes currently configured. 

</quote>

http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/F1A1B4B1/2.9

> With OMPROUTE (OSPF) does CommServer override ... a static route?

Yes, if permitted by the specification of REPLACEABLE on the ROUTE statement.

> I am told the static routes in CommServer are only honoured until the dynamic 
> routes get in the routing tables.[1]

You have been told correctly - perhaps by someone who has read the description 
of the ROUTE statement - assuming, of course, that REPLACEABLE has been 
specified on the ROUTE statement.

> And then I'm told these dynamic routes will take preference to the static 
> routes.

The issue - and I mean "issue" in its traditional sense, not the recently 
emerged euphemism so favoured between the shining seas but most regrettably 
spreading throughout the supposedly English-speaking world - does not arise. 
The replaced static routes will have disappeared. Check the display of the 
routing table, the actual one, NETSTAT ROUTE, not the OMPROUTE one.

Perhaps you need to appreciate that the IP logic of Communications Server 
provides an API for OMPROUTE to use in order to manage the routing table. I 
first encountered probably a rudimentary version of this API when teaching 
myself the socket API from the description of the C sockets API, the only API - 
not counting Pascal - at the time. Among the options of the ioctl() call, you 
find the so-called "commands" SIOCADDRT and SIOCDELRT. That - together with the 
rtrouteh.h structure - told me all I needed to know about how dynamic routing 
protocol programs worked.

> Does this mean that CommServer's OSPF can override ... a ... route <that> ... 
> was established with a static definition?

Yes.

Be aware that the operation of the routing table can these days be adjusted by 
use of "Policy-based routing" - I assume based on the name of the function. 
This is a function with which I have yet to acquaint myself.

http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/F1A1B3B1/1.6.17

-

[1] Note that, since I was obliged to correct a couple of typos, I took a 
liberty in correcting another!

-

Chris Mason

On Fri, 23 Nov 2012 11:42:27 -0600, Hansen, Dave L - Eagan, MN 
<[email protected]> wrote:

>Group,
>
>   We are embattled over the question of static routes.  We are running z/OS 
> V1R13.  I believe that static routes are always preferred over dynamic routes 
> (there are some exceptions if the Administrative Distance - AD is changed).  
> And that changing a static route requires manual intervention.
>
>Q).  With OMPROUTE (OSPF) does CommServer override or reset a static route?  I 
>am told the static routes in CommServer are only honored utill the dynamic 
>routes get in the routing tables.  And then I'm told these dynamic routes will 
>take preference to the static routes.  Does this mean that CommServer's OSPF 
>can override or select a different route than what was established with a 
>static definition?
>
>
>   Thank you,  Dave
>
>
>Dave Hansen

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