TMS zl Management and Configuration Guide ST.1.2.100916

B-7
Glossary
Data Encryption
Standard
See DES.
data port Physical port 1 on the TMS zl Module (J1 on the circuit board), which plugs
into the host switch backplane. In routing mode, the data port is a tagged
member of every TMS VLAN. In monitor mode, the data port receives mirrored
traffic from the host switch.
dead interval The amount of time an OSPF router waits for route advertisements from a peer
router before declaring a route dead.
default gateway The next-hop router to which a device sends all traffic that is destined to a
different network or subnet.
default metric The metric that is assigned to redistributed routes.
defragmentation The reassembly of fragmented packets, often performed by a router or by the
TMS zl Module.
demilitarized zone See DMZ.
denial of service See DoS.
deny An action for an IPsec policy. Deny means that the traffic that is specified in
the traffic selector is discarded and is not passed through the IPsec tunnel. See
also Bypass and Apply.
DER Distinguished Encoding Rules. A method for encoding data objects. For more
information, see ITU-T X.690 at http://www.itu.int/ITU-T/studygroups/
com17/languages/X.690-0207.pdf.
DES Data Encryption Standard. A published symmetric encryption algorithm
used for IPsec that uses a 56-bit symmetric key to encrypt data in 64-bit blocks.
For more information, see FIPS PUB 46-3 at http://csrc.nist.gov/publications/
fips/fips46-3/fips46-3.pdf.
designated router See DR.
destination NAT Network address translation in which the destination IP address is replaced
by another IP address as the packet crosses a network boundary.
destination zone The zone to which a packet is destined.
DF bit Don’t Fragment bit. The IP header bit that specifies whether the packet can
be fragmented.
DH See Diffie-Hellman key exchange.