Changing static routes with SMIT

[dcomit]

I've met most flavours of unix but aix is a new one on me!

I need to change some static routes using SMIT - I have no documentation so could someone tell me how to do it or refer me to an idiot's guide.

Also, do I need to map my terminal emulator's function keys as I can't get F1 - help or F3 - cancel to work.

Thanks

 

[crowe]

For and of the F keys, Escape plus the number will usually work. So F1 would be ESC then 1.

For routes, check out:

smitty -> communications applications & services -> TCP/IP -> further configuration -> static routes

crowe

 

[dcomit]

Thanks for that. Does "flush routing table" delete all the routes permanently?

 

[PSD]

dcomit,

You have the option to remove in current system and from the ODM configuration database. i.e. the place where the static routes are stored to be retained after reboot. The ODM is AIX specific.

If you select the option :

Flush IPV4 routes in config. database = yes

Then it remove all static routes permanently, if not on reboot they will re-appear.

N.B. this will also remove your default gateway or router so afterwards
do:

smitty tcpip
select en0
and press return on the menu screen

F10 to exit or escape 0

Then on the command line type:
netstat -r

and you should have a default gateway.....

Cheers

PSD
IBM Certified Specialist - AIX V4.3 Systems Support
IBM Certified Specialist - AIX V4 HACMP

 

[dcomit]

Thanks. Can you tell me what cloned routes are and how can I delete them?

 

[aixqueen]

Cloning routes in 4.3.3
add to rc.net also......They need to be before /usr/lib/methods/definet.
#no -o tcp_pmtu_discover=0
#no -o udp_pmtu_discover=0
. This values are set to 1 by default in AIX 4.3.3.
Which means clone routes....if you don't want cloned
routes change to zero.

Here is where it is (near the bottom) in the rc.net file:
at the very bottom.....
/usr/sbin/no -o extendednetstats=0 >>/dev/null 2>&1
if [ -f /usr/sbin/no ] ; then
/usr/sbin/no -o tcp_sendspace=65536
/usr/sbin/no -o tcp_recvspace=65536
/usr/sbin/no -o tcp_pmtu_discover=0
/usr/sbin/no -o udp_pmtu_discover=0
no -o tcp_pmtu_discover=0
#no -o udp_pmtu_discover=0

/usr/sbin/no -o ipforwarding=1
/usr/sbin/no -o tcp_pmtu_discover=0
/usr/sbin/no -o udp_pmtu_discover=0
fi
============================================
Routes Routes You have to Have Routes!
To create/delete routes in AIX.
the chinet command (which smitty route uses) stores the route in the
ODM. These types of routes will be automatically recreated upon
reboot.

OR the route add/delete command
Which creates the route, but does not store them in the ODM and
hence are lost upon reboot (unless a script is run from /etc/inittab to
recreate them or add to /etc/rc.net).

How do you tell if a route is in the ODM or not (besides rebooting to
see if it comes back)?
lsattr -El inet0

How do you clear a routing table? route -f (flush)

Add static routes with smitty smit mkroute or :
chdev -l inet0 -a addroute=XXXXXXXXXXXXXXXXXX
Remove static routes with smitty smit rmroute :
chdev -l inet0 -a delroute=XXXXXXXXXXXXXXXXXX

chdev -l inet0 -a
delroute=net,destination_address,gateway,subnet_mask -
chdev calls a routine that will delete the route from the ODM.

 

[aixqueen]

AIX supports a path MTU discovery algorithm as described in RFC 1191. Path MTU
discovery can be enabled for TCP and UDP applications by modifying the
tcp_pmtu_discover and udp_pmtu_discover options of the no command. When
enabled for TCP, path MTU discovery will automatically force the size of all packets
transmitted by TCP applications to not exceed the path MTU. Since UDP applications
themselves determine the size of their transmitted packets, UDP applications must be
specifically written to utilize path MTU information by using the IP_FINDPMTU
socket option, even if the udp_pmtu_discover no option is enabled. By default, the
tcp_pmtu_discover and udp_pmtu_discover options are disabled.

When the path MTU has been discovered for a network route, a separate host route is
cloned for the path. These cloned host routes, as well as the path MTU value for the
route, can be displayed using the netstat -r command. Accumulation of cloned routes
can be avoided by allowing unused routes to expire and be deleted. Route expiration is
controlled by the route_expire option of the no command. Route expiration is disabled
by default.

 

[dcomit]

aixqueen,

Thanks for the info.

Do I understand you correctly, that the only way to get rid of cloned routes is to clear the entire routing table?

If there is another way I'd be glad to know it - we have a 7/24 operation and I don't fancy deleting and rebuilding the entire routing table.

 

[aixqueen]

no you do not have to clear the table
just do the two no commands from the command line

/usr/sbin/no -o tcp_pmtu_discover=0
/usr/sbin/no -o udp_pmtu_discover=0

and for the next reboot add the two lines to the /etc/rc.net file
that will stop cloned routes immediately and then
not start them on next reboot.

Here is where it is (near the bottom) in the rc.net file:
at the very bottom.....
/usr/sbin/no -o extendednetstats=0 >>/dev/null 2>&1
if [ -f /usr/sbin/no ] ; then
/usr/sbin/no -o tcp_sendspace=65536
/usr/sbin/no -o tcp_recvspace=65536
/usr/sbin/no -o tcp_pmtu_discover=0
/usr/sbin/no -o udp_pmtu_discover=0
fi