In Viptela SDWAN, what is the significance of transport color?

[muthumohan]

Hello All,

In SDWAN, what exactly does color mean? Does it simply indicate the type of transport such as mpls, lte etc. or there is more to it?

Do we have use only those pre-defined color in the 'color' command or I can use any color such as pink, yellow etc. (forgive me if this looks stupid, but Cisco documents does not clarify such things)

Does color has anything to do with Private IP and Public IPs on the vEdge?

Would appreciate any help.

Regards,

Mohan

PS: I see there are many mistakes in the SDWAN documentation. Has anyone observed these?

[gilbert.aispuro1]

Hello,
Selecting a Color is a personal preference, ultimately identifying a transport/ISP-connection that you can reference, such as a tag.

For all my sites, I have 3 ISP connections. I identify them as Gold, Silver and Bronze. Gold being best, . . etc.

[@confignetworks]

Hello, 

  This is coming from Cisco validated Design: 

Color
On vEdge routers, the color attribute helps to identify an individual WAN transport tunnel. You cannot use the
same color twice on a single vEdge router.
Colors by themselves have significance. The colors metro-ethernet, mpls, and private1, private2, private3,
private4, private5, and private6 are considered private colors. They are intended to be used for private networks
or in places where you will have no NAT addressing of the transport IP endpoints, as the expectation is that there
is no NAT between two endpoints of the same color. When a vEdge router uses a private color, it will attempt
to build IPSec tunnels to other vEdge routers using the native, private, underlay IP. The public colors are 3g, biz,
internet, blue, bronze, custom1, custom2, custom3, default, gold, green, lte, public-internet, red, and silver. With
public colors, vEdge routers will try to build tunnels to the post-NAT IP address (if there is NAT involved).
If you are using a private color and need NAT to communicate to another private color, the carrier setting in the
configuration dictates whether you use the private or public IP address. Using this setting, two private colors will
establish a session when one or both are using NAT.

Please note also that colors are also used for TLOCs. Each TLOC in a specific Color will connect to a remote TLOC in the same color or different Color. This point depends on the configuration. 

Here is the CVD: https://www.cisco.com/c/dam/en/us/td/docs/solutions/CVD/SDWAN/CVD-SD-WAN-Design-2018OCT.pdf

Best regards, 

[osdesent]

The color is relevant whenever the IPsec Tunnels for the data plane are created in order to know if pre-nated or post-nated IP destination should be used to create the tunnel. Usually Private colors are relevant for private transports like MPLS, ME, etc and Public colors like the Internet.

By default all colors will try to stablish tunnels with all other colors unless you "restrict" the tunnels...for instance, public colors just talk with public colors and privates with private colors.

Finally the public IP and privates IP are not bound to colors however it makes sense a public color like the internet has a public IP but it is not always the case, imagine that you put an Edge being a FW doing PAT...in this case the TLOC most likely would have a private IP being PATed on the FW to get internet access.