Cisco Cisco Expressway
3
Guide to this document: format of information
Expressway-E
source port
Server
listening port
Management control
DMZ to public
Open firewall
DMZ to public
IP address
IP address of
Expressway-E
IP address of DNS
server
IP Po
rt
s
DNS
UDP S
>= 1024
UDP 53
53
S = Source port , typically >= 1024
Destination of messaging
Source of messaging
Destination of messaging: IP port
• letter reference for more details
• default / expected port range in italics
• default / expected port range in italics
Source of messaging: IP port
• letter reference for more details
• default / expected port range in italics
• default / expected port range in italics
Firewall needs to have a pinhole open for at least
• all source ports at IP address of source
to
• all listening ports at IP address of listener
Destination of messaging: IP address
Source of messaging: IP address
When a firewall allows an outbound message through, it is
assumed that responses (up to about 20 to 30 seconds after
the original send) will be allowed back through the firewall
assumed that responses (up to about 20 to 30 seconds after
the original send) will be allowed back through the firewall
Details of what defines
the IP port ID / range
the IP port ID / range
Direction of management / calls
Direction firewall needs to be opened
Internet
Expressway-C
Expressway-E
DMZ