SW-SEC-016LowCisco Catalyst and Nexus

VTP in server or client mode

Base severity

Low

Area

Interfaces and Segmentation

Platform

Cisco Catalyst and Nexus

Evidence level

Fact1.00

Benchmark reference

Reads the export, not the device

ConfigProof reads a configuration export. This control is evaluated against the objects in that file, and it reports what the file says. It does not connect to the device and sees no traffic, so a finding here describes the configuration, not what the firewall is doing right now.

Why it matters

A switch with a higher VTP revision joining the domain can overwrite or delete every VLAN on every switch in it.

How to fix it

Web interface

The steps below are written for the web interface. A finding raised on your own export carries the same steps with your object names filled in.

Use VTP transparent (or off), or VTP version 3 with a primary server and a domain password.

Cisco IOS-XE CLI

configure terminalvtp mode transparentendwrite memory

An example. Values in angle brackets are yours to supply; a finding on your own export fills in the names it read. Typed in configuration mode; copy running-config startup-config saves it, with no separate commit. Read every line first.

Read it back

show vtp status

Before you type it2

Written from the Cisco IOS-XE 17 and NX-OS 9 and 10 command references and not run on a device: read each line before you paste it.
On a Nexus (NX-OS) switch the same change is typed with NX-OS syntax; check the NX-OS configuration guide for the equivalent command.

How to confirm the fix

show vtp status shows transparent or off mode.

Limits

No limitation is recorded for this control beyond the one that applies to all of them: it reads a configuration export.

Compliance references

No benchmark recommendation is mapped to this control in this version.

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