IBM Support

OMPROUTE Send Request Blocked at Startup

Troubleshooting


Problem

Occasionally during startup of TCPIP (such as after an IPL), there is an EZZ8052I message issued by OMPROUTE stating that a SEND request has been blocked.

Symptom


   EZZ8052I OMPROUTE SEND TO 224.0.0.5 BLOCKED BY TCPIP

Cause

IPSECURITY has been configured on the IPCONFIG (or IPCONFIG6) statement in the TCPIP PROFILE. By default, all IP traffic is blocked until the Policy Agent process has installed the defined rules in the TCPIP stack. If OMPROUTE sends an OSPF HELLO packet before the rules are installed, it will get an error indication that is reflected by this message.

Resolving The Problem

Add an IPSEC section to the TCPIP PROFILE, specifying the default filter rules for the stack to use prior to Policy Agent initialization. The following sample shows the minimum needed to allow OMPROUTE to function:

   IPSEC
   ;   Rule       Src Dst   Logging Protocol
   ; OSPF protocol used by Omproute
       IPSECRule  *   *    NOLOG   PROTO OSPF
   ; IGMP protocol used by Omproute
       IPSECRule  *   *    NOLOG   PROTO 2
   ; RIP protocol used by Omproute (if enabled)
       IPSECRule  *   *    NOLOG   PROTO UDP SRCPORT 520 DESTPORT *
       IPSECRule  *   *    NOLOG   PROTO UDP SRCPORT *   DESTPORT 520
   ; IPv6 OSPF protocol used by Omproute (if enabled)
       IPSEC6Rule *   *    NOLOG   PROTO OSPF
   ; IGMP protocol used by Omproute (if updated)
       IPSEC6Rule *   *    NOLOG   PROTO 2
   ; IPv6 RIP protocol used by Omproute (if enabled)
       IPSEC6Rule *   *    NOLOG   PROTO UDP SRCPORT 521 DESTPORT *
       IPSEC6Rule *   *    NOLOG   PROTO UDP SRCPORT *   DESTPORT 521
     ENDIPSEC

You will want to consider adding other rules for minimal access as well (such as allowing connections to TN3270 or z/OSMF from computer room workstations).

[{"Product":{"code":"SSSN3L","label":"z\/OS Communications Server"},"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Component":"--","Platform":[{"code":"PF035","label":"z\/OS"}],"Version":"1.6;1.7;1.8;1.9;1.10;1.11;1.12;1.13;2.1;2.2;2.3","Edition":"","Line of Business":{"code":"LOB35","label":"Mainframe SW"}}]

Document Information

Modified date:
23 June 2018

UID

swg21412615