An AIX system should have a single default gateway defined. However, sometimes, it does occur that a system has multiple default gateways. Here's information to detect multiple default gateways and how to get rid of them:

First, obtain how many gateways there are:

# odmget -q "attribute=route" CuAt

CuAt:
        name = "inet0"
        attribute = "route"
        value = "net,-hopcount,0,,0,192.168.0.1"
        type = "R"
        generic = "DU"
        rep = "s"
        nls_index = 0

CuAt:
        name = "inet0"
        attribute = "route"
        value = "net,-hopcount,0,,0,192.168.0.2"
        type = "R"
        generic = "DU"
        rep = "s"
        nls_index = 0

# chdev -l inet0 -a delroute="net,-hopcount,0,,0,192.168.0.2"
Method error (/usr/lib/methods/chginet):
        0514-068 Cause not known.
0821-279 writing to routing socket: The process does not exist.
route: not in table or multiple matches
0821-207 chginet: Cannot add route record to CuAt.

# odmget -q "attribute=route" CuAt

CuAt:
        name = "inet0"
        attribute = "route"
        value = "net,-hopcount,0,,0,192.168.0.1"
        type = "R"
        generic = "DU"
        rep = "s"
        nls_index = 0

You can automatically forward all error report entries to your email. This next part describes how to do that.

Create a file like this:

# cat /tmp/mailgeorge
errnotify:
  en_name="mailgeorge"
  en_persistenceflg=1
  en_method="errpt -a -l $1|mail -s \"errpt: $9\" george@email.com"

# odmadd /tmp/mailgeorge

# errlogger "My coffee is cold"

# errpt -a
----------------------------------------------------
LABEL:          OPMSG
IDENTIFIER:     AA8AB241

Date/Time:       Tue Oct  6 15:57:58 CDT 2009
Sequence Number: 585
Machine Id:      0004D6EC4C00
Node Id:         hostname
Class:           O
Type:            TEMP
Resource Name:   OPERATOR

Description
OPERATOR NOTIFICATION

User Causes
ERRLOGGER COMMAND

        Recommended Actions
        REVIEW DETAILED DATA

Detail Data
MESSAGE FROM ERRLOGGER COMMAND
My coffee is cold

# errclear 0

# odmdelete -q 'en_name=mailgeorge' -o errnotify

From powerlink.emc.com:

1. Before making any changes, collect host logs to document the current configuration. At a minimum, save the following: inq, lsdev -Cc disk, lsdev -Cc adapter, lspv, and lsvg
2. Shutdown the application(s), unmount the file system(s), and varyoff all volume groups except for rootvg. Do not export the volume groups.

   # varyoffvg <vg_name>

   Check with lsvg -o (confirm that only rootvg is varied on)
   If no PowerPath, skip all steps with power names.
3. For CLARiiON configuration, if Navisphere Agent is running, stop it:

   # /etc/rc.agent stop

4. Remove paths from Powerpath configuration:

   # powermt remove hba=all

5. Delete all hdiskpower devices:

   # lsdev -Cc disk -Fname | grep power | xargs -n1 rmdev -dl

6. Remove the PowerPath driver instance:

   # rmdev -dl powerpath0

7. Delete all hdisk devices:
   For Symmetrix devices, use this command:

   # lsdev -CtSYMM* -Fname | xargs -n1 rmdev -dl

   For CLARiiON devices, use this command:

   # lsdev -CtCLAR* -Fname | xargs -n1 rmdev -dl

8. Confirm with lsdev -Cc disk that there are no EMC hdisks or hdiskpowers.
9. Remove all Fiber driver instances:

   # rmdev -Rdl fscsiX

   (X being driver instance number, i.e. 0,1,2, etc.)
10. Verify through lsdev -Cc driver that there are no more fiber driver instances (fscsi).
11. Change the adapter instances in Defined state

    # rmdev -l fcsX

    (X being adapter instance number, i.e. 0,1,2, etc.)
12. Create the hdisk entries for all EMC devices:

    # emc_cfgmgr

    or

    # cfgmgr -vl fcsx

    (x being each adapter instance which was rebuilt). Skip this part if no PowerPath.
13. Configure all EMC devices into PowerPath:

    # powermt config

14. Check the system to see if it now displays correctly:

    # powermt display
    # powermt display dev=all
    # lsdev -Cc disk
    # /etc/rc.agent start

Sometimes situations occur where a logical volume is deleted, but the ODM is not up to date. E.g. when "lsvg -l" doesn't show you the logical volume, but the lslv command can still show information about the logical volume. Not good.

To resolve this issue, first try:

# synclvodm -v [volume group name]

# odmget -q name=hd7 CuDv | tee -a /tmp/CuDv.hd7.out
# odmget -q name=hd7 CuAt | tee -a /tmp/CuAt.hd7.out

# odmadd /tmp/[filename]

# odmdelete -o CuDv -q name=hd7
# odmdelete -o CuAt -q name=hd7