A-14
Cisco ASA 5500 Series Configuration Guide using ASDM
Appendix A Addresses, Protocols, and Ports
Local Ports and Protocols
Local Ports and Protocols
Table A-8 lists the protocols, TCP ports, and UDP ports that the ASA may open to process traffic
destined to the ASA. Unless you enable the features and services listed in Table A-8, the ASA does not
open any local protocols or any TCP or UDP ports. You must configure a feature or service for the ASA
to open the default listening protocol or port. In many cases you can configure ports other than the
default port when you enable a feature or service.
tftp UDP 69 Trivial File Transfer Protocol
time UDP 37 Time
uucp TCP 540 UNIX-to-UNIX Copy Program
who UDP 513 Who
whois TCP 43 Who Is
www TCP 80 World Wide Web
xdmcp UDP 177 X Display Manager Control Protocol
Table A-7 Port Literal Values (continued)
Literal TCP or UDP? Value Description
Table A-8 Protocols and Ports Opened by Features and Services
Feature or Service Protocol Port Number Comments
DHCP UDP 67,68 —
Failover Control 105 N/A —
HTTP TCP 80 —
HTTPS TCP 443 —
ICMP 1 N/A —
IGMP 2 N/A Protocol only open on destination IP
address 224.0.0.1
ISAKMP/IKE UDP 500 Configurable.
IPsec (ESP) 50 N/A —
IPsec over UDP
(NAT-T)
UDP 4500 —
IPsec over UDP
(Cisco VPN 3000
Series compatible)
UDP 10000 Configurable.
IPsec over TCP
(CTCP)
TCP — No default port is used. You must specify
the port number when configuring IPsec
over TCP.
NTP UDP 123 —
OSPF 89 N/A Protocol only open on destination IP
address 224.0.0.5 and 224.0.0.6
