Running Cisco DCNM Behind a Firewall

This chapter provides information about running Cisco DCNM behind a firewall.

Running Cisco DCNM Behind a Firewall

Generally, an Enterprise (external world) and Datacenter is separated by a firewall, i.e., DCNM is configured behind a firewall. The Cisco DCNM Web Client and SSH connectivity must pass-through that firewall. Also, a firewall can be placed between the DCNM Server and DCNM-managed devices.

All Cisco DCNM Native HA nodes must be on the same side of the firewall. The internal DCNM Native HA ports are not listed, as it is not recommended to configure a firewall in between the Native HA nodes.

Any standard port where the Ingress traffic enters from clients cannot be modified unless you disable the local firewall.

The following table lists all ports that are used for communication between Cisco DCNM Web Client, SSH Client, and Cisco DCNM Server.

Port Number

Protocol

Service Name

Direction of Communication

Remarks

22

TCP

SSH

Client to DCNM Server

SSH access to external world is optional.

443

TCP

HTTPS

Client to DCNM Server

This is needed to reach DCNM Web Server.

The following table lists all ports that are used for communication between Cisco DCNM Server and other services.


Note

The services can be hosted on either side of the firewall.

Port Number

Protocol

Service Name

Direction of Communication

Remarks

49

TCP/UDP

TACACS+

DCNM Server to DNS Server

ACS Server can be either side of the firewall.

53

TCP/UDP

DNS

DCNM Server to DNS Server

DNS Server can be either side of the firewall.

123

UDP

NTP

DCNM Server to NTP Server

NTP Server can be either side of the firewall.

5000

TCP

Docker Registry

Incoming to DCNM Server

Docker Registry Service on DCNM Server listening to requests from DCNM compute nodes.

5432

TCP

Postgres

DCNM Server to Postgres DB Server

Default installation of DCNM does not need this port.

This is needed only when Postgres is installed external to the DCNM host machine.

The following table lists all ports that are used for communication between DCNM Server and managed devices:

Port Number

Protocol

Service Name

Direction of Communication

Remarks

22

TCP

SSH

Both Direction

DCNM Server to Device – To manage devices.

Device to DCNM Server – SCP (POAP).

67

UDO

DHCP

Device to DCNM Server

69

TCP

TFTP

Device to DCNM Server

Required for POAP

161

TCP/UDP

SNMP

Server to DCNM Device

DCNM configured via server.properties to use TCP uses TCP port 161, instead of UDP port 161.

514

UDP

Syslog

Device to DCNM Server

2162

UDP

SNMP_TRAP

Device to DCNM Server

33000-33499

TCP

gRPC

Device to DCNM Server

LAN Telemetry Streaming