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Problem IT22185
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Status: Closed |
ON A NAT ENVIRONMENT WITH THE REGISTRY VARIABLE DB2_HADR_NO_IP_CHECK TURNED ON, HAS ISSUES WITH MULTIPLE HADR STANDBYS. |
| product: |
DB2 FOR LUW / DB2FORLUW / B10 - DB2 |
| Problem description: |
Currently DB2 does not support DB2_HADR_NO_IP_CHECK with
multiple standbys.
It would require a change to the DB2 product.
The principle standby has address X, but it sits behind a router
which does NAT to translate address X to Y.
The standby makes a connection to the primary. This forms a
TCP/IP connection via a 3-way TCP handshake. During this
handshake and all subsequent messages, the principle standby
constructs a network packet with TCP and IP headers. These
headers contain the address X as the source address. When the
packet goes through the router, source address X is changed to Y
in the TCP/IP header. The primary receives these packets with a
TCP/IP header indicating that it was sent by source address Y.
When the primary responds, it creates a TCP/IP header indicating
Y is the destination address. When this reaches the router, it
changes the destination address from Y to X and forwards it to
the standby.
After the TCP/IP connection forms, the primary prints the
address of the connection. This comes from the TCP/IP header,
so it is address Y. Later on, the primary receives the full
handshake message. This looks at the source address in the
handshake message, which is address X. Therefore the addresses
do not match.
The solution requires an update to the product by IBM and a
special configuration by the customer.
When a remote host is behind a NAT, then the local host should
be set up with the following configuration ...
- Set DB2_HADR_NO_IP_CHECK to true
- Configure HADR_TARGET_LIST using the address of the NAT
router.
- Configure HADR_TARGET_LIST using the port specified by remote
host's HADR_LOCAL_SVC.
- Configure port forwarding on the NAT router so that any
message sent to the router's HADR_LOCAL_SVC will be forwarded to
HADR_LOCAL_ADDR. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* ALL *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to Db2 11.1 Mod 3 Fix Pack 3 or higher *
**************************************************************** |
| Local Fix: |
|
| available fix packs: |
Db2 Version 11.1 Mod 3 Fix Pack 3 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod3 Fix Pack3 iFix001 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod3 Fix Pack3 iFix002 for Linux, UNIX, and Windows
|
| Solution |
First fixed in Db2 11.1 Mod 3 Fix Pack 3 |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 29.08.2017
19.03.2018
19.03.2018 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
