TMS zl Management and Configuration Guide ST.1.1.100430

B-23
Glossary
PCM+ ProCurve Manager Plus. The HP ProCurve network management platform.
PDU Protocol Data Unit. The unit that gives the protocol control information,
either the bit (Layer 1), the frame (Layer 2), the packet (Layer 3), the segment
(Layer 4) or the data (all other layers).
peer In VPNs, the peers are the two ends of the VPN tunnel.
peer ID The identifier of the remote router in a site-to-site VPN. Generally the peer ID
is the IP address of the router on the interface through which the VPN is
established.
PEM Privacy Enhanced Mail. An IETF proposal to secure emails with public keys.
PEM depends on prior distribution of a hierarchical PKI with a single root. For
more information, see RFCs 1421–1424 at http://www.ietf.org/rfc.html.
per-hop behavior See PHB.
perfect forward
secrecy
See PFS.
persistent tunnel An IPsec SA configured as a persistent tunnel always remains open. It is
renewed even if it remains inactive longer than the tunnel lifetime.
PFS Perfect Forward Secrecy. A key-establishment protocol that is used to secure
VPN connections, wherein the key that was used to protect the transmission
of data is not used to derive any additional keys.
PHB Per-Hop Behavior. Defines how packets are queued at network nodes.
PIM-SM Protocol Independent Multicast sparse mode. A protocol used to efficiently
route traffic to multicast groups that span wide-area (WAN and inter-domain)
internets. For more information, see RFCs 2365 at www.ietf.org/rfc/
rfc2362.txt.
ping of death An attack in which the attacker sends a ping packet that is larger than 65535
bytes. Ping packets this large cause the victim device to crash, causing a DoS.
PMTU Path Maximum Transmission Unit. A technique for detecting the maximum
size for an IP packet along a particular path. For more information, see RFC
1191 at http://www.ietf.org/rfc/rfc1191.txt.
poison reverse In RIP, a poison reverse message tells a router that a route in the routing table
is no longer connected. This helps to speed convergence.
policy group A set of policies (firewall or NAT) that have the same source and destination
zones.