HP-UX IPSec version A.02.01 Administrator's Guide

Product Specifications
Product Restrictions
Appendix A6
IKE Limitations
IKE limitations and constraints are described below:
• For Main Mode (MM) and Quick Mode (QM) transaction exchanges, a
single transaction request will timeout after 31 seconds (five
retransmissions using an exponential timer, starting at one second)
which in turn will timeout or terminate the transaction negotiation.
When timeouts occur, they usually occur during heavy network
traffic congestion. It is the responsibility of the application to try to
re-establish the connection after a connection establishment failure.
When using certificate-based IKE authentication (RSA signatures),
HP-UX IPSec checks that the identity sent by the other node in the
Main Mode (MM) negotiation matches information in the other
node’s certificate. By default, HP-UX IPSec sends its local IP address
as its ID value and the appropriate IP address type (IPv4 or IPv6) as
the ID type as the ISAKMP ID payload in IKE Phase 1 exchanges.
HP-UX IPSec accepts the following ID types from nodes it
communicates with:
— IPv4 address (ID_IPV4_ADDR)
— IPv6 address (ID_IPV6_ADDR)
— Fully Qualified Domain Name (ID_FQDN)
— User-Fully Qualified Domain Name (ID_USER_FQDN)
— X.509 Subject Distinguished Name (DN, ID_DER_ASN1_DN)
IPv4 ICMP Messages
Discarding or requiring IPv4 ICMP messages (Internet Control Message
Protocol messages, IP protocol value 1) to be encrypted or authenticated
may cause connectivity problems. Normal network operation may
require IP to exchange ICMP messages between end-to-end hosts and
between an end host and an IP gateway (including router devices). IP
may need to exchange ICMP packets with gateway nodes even though no
user (end-to-end) services are being used to the gateways.
Be careful when configuring the default IPsec policy or IPsec policies
that affect entire subnets, because you may inadvertently cause ICMP
messages to be discarded. You may also inadvertently require ICMP