Proxy ARP Not Supported
APAR Identifier ...... PQ37902 Last Changed ........ 00/11/01
PROXY ARP NOT SUPPORTED
Symptom ...... IN INCORROUT Status ........... CLOSED PER
Severity ................... 3 Date Closed ......... 00/07/31
Component .......... 5735FAL00 Duplicate of ........
Reported Release ......... 320 Fixed Release ............ 999
Component Name TCP/IP V2 FOR V Special Notice
Current Target Date .. Flags
SCP ...................
Platform ............
Status Detail: SHIPMENT - Packaged solution is available for
shipment.
PE PTF List:
PTF List:
Release 310 : UQ45715 available 00/08/04 (0002 )
Release 320 : UQ45716 available 00/11/01 (0002 )
Parent APAR:
Child APAR list:
ERROR DESCRIPTION:
VM TCP/IP does not support proxy ARP. A point-to-point link
connected to VM TCP/IP cannot use an IP address in a subnetwork
LAN that is connected to this same VM TCP/IP host. In addition,
the lack of proxy ARP support makes the process of assigning IP
addresses unnecessarily difficult and leads to configuration
errors that are difficult to explain. Proxy ARP support will
facilitate the use of virtual point-to-point links to connect
other VM GUESTS (e.g., Linux for S/390) to VM TCP/IP.
LOCAL FIX:
PROBLEM SUMMARY:
****************************************************************
* USERS AFFECTED: Users with point-to-point connections *
* between VM TCP/IP and other virtual machines *
* (for example, Linux) that use an IP address *
* in the same subnet as those used by VM *
* TCP/IP on a Local Area Network. *
****************************************************************
* PROBLEM DESCRIPTION: *
****************************************************************
* RECOMMENDATION: APPLY PTF *
****************************************************************
VM TCP/IP does not support Proxy ARP. As a result,
point-to-point connections to other guests (for example, a
virtual CTCA connection to a Linux guest) cannot use IP
addresses that are in the same subnetwork as IP addresses on a
Local Area Network connected to VM TCP/IP. While using a
different subnetwork allows such a connection to be
established, in some circumstances this is not possible.
A new AssortedParms keyword (PROXYARP) allows VM to act as a
proxy for guests using point-to-point connections (CTCA and
IUCV). ARP requests for the MAC address associated with the IP
address of a point-to-point connection are answered by VM
TCP/IP on behalf of the guest, causing traffic to be routed to
VM for forwarding to the ultimate destination.
PROBLEM CONCLUSION:
Include the PROXYARP operand of the AssortedParms statement in
PROFILE TCPIP to allow IP addresses for point-to-point links to
be in the same subnet as IP addresses used on LANs to which VM
TCP/IP has a connection.
In addition to the Proxy ARP support provided via this APAR,
the information that follows will be included in any future
updates to the following publication(s):
--------------------------------------------------------------
SC24-5847-00 -- TCP/IP Function Level 310 Planning and
Customization
Affected Section: Chapter 6, "Configuring the TCP/IP
Virtual Machine", p. 48
SC24-5847-01 -- TCP/IP Function Level 320 Planning and
Customization
Affected Section: Chapter 4, "Configuring the TCP/IP
Server", p. 50
==============================================================
A description of the PROXYARP parameter is added, which should
read as follows:
PROXYARP
Causes the VM/ESA host where TCP/IP is running to act as a
proxy for guest hosts that use point-to-point connections
(for example, Channel-to-Channel and IUCV connections). ARP
requests for the MAC address associated with the IP address
of a point-to-point connection are answered by TCP/IP on
behalf of the guest, which causes traffic to be routed to VM
for forwarding to the ultimate destination.
PROXYARP should be specified when the IP address for a host
associated with a point-to-point connection is in the same
subnet as other IP addresses which are in use on
LANs to which VM/ESA host (that is providing guest support)
has a connection.
TEMPORARY FIX:
COMMENTS:
**** PE00/09/15 FIX IN ERROR. SEE APAR PQ41584 FOR DESCRIPTION
MODULES/MACROS: MSTCP TCARP TCPARSE TCPIP
SRLS: SC24584700 SC24584701
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