3845 - Etherswitch module and NAT

[mikeleecha]

Hello. Does a 3845 with the 4 port Etherswitch HWIC support NAT across the Etherswitch ports? For example, let's say I have 2 vlans (10 and 20) and assign ports 0 and 1 on the Etherswitch card to vlan 10. Ports 2 and 3 go to vlan 20. I create Layer 3 Vlan interfaces for both. Can I NAT across the two Vlan interfaces on a 3845?

Thanks.

[thisisshanky]

Good question, I have no clue, I couldnt find a ref. to it in the release notes, (unless I missed something)..it will be good to find out if it does support. if ou have a hwic-4esw, you might as well as try nat command (ip nat inside/outside) on the respective vlans.

[Enes Simnica]

Hello from the future @mikeleecha (lol)!! Yes, the Cisco 3845 with the 4-port Etherswitch HWIC does support NAT across VLAN interfaces. In your scenario, you can assign ports to VLAN 10 and VLAN 20, create Layer 3 interfaces for both, and then configure NAT between them. This setup will let you manage traffic between the two VLANs.

Apologies for the slight delay—only about 19 years late on this one!

-Enes

[marce1000]

 - @Enes Simnica - Appreciating your efforts , but it does not make much sense : poster may be retired , during other work
                              at another company , having a  career sabbat break , learned fishing....

 M.

[Joseph W. Doherty]

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@marce1000 wrote:

 - @Enes Simnica - Appreciating your efforts , but it does not make much sense : poster may be retired , during other work
                              at another company , having a  career sabbat break , learned fishing....

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Like @marce1000 I often wonder why someone bothers making a reply to a multiple years (in this case, almost multiple decades) old thread.  Especially, when such replies are a rehash of already provided information and don't provide anything new.

However, in this case, @Enes Simnica recognizes original thread is about 19 years old, but more importantly, original OP's question was never actually correctly answered!

One could ask whether the original OP question, itself, really needs to be answered at this point in time.  Probably not many will bump into this issue on a 3845 using a HWIC Ethernet module, except, perhaps, for a 3845 being used personally.  But let's also not forget others may search (or should search) these forums looking for an answer for a similar problem

Also, even some current Cisco routers have a similar issue.  For example, I've recently have seen similar questions on how to do L3 on C1100 series' L2 ports.

In this case, I believe @Enes Simnica really made a worthwhile contribution, but if Enes also had in mind other platforms, including current platforms, that could have the same "problem" and "solution", it would be even better to mention that explicitly.

[marce1000]

.

 @Joseph W. Doherty As far as giving additional info's on the issue that is always ok. But as far as reaching out I doubt it worked. 

 M.

[Joseph W. Doherty]

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@marce1000 wrote:

.

 @Joseph W. Doherty As far as giving additional info's on the issue that is always ok. But as far as reaching out I doubt it worked. 

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100% agree, likely OP isn't still waiting at this terminal/PC for an answers (or it's like a cartoon image of a skeleton with cobwebs - laugh), but "home" users possibly might have obtained something like a 3845 from eBay, and trying stuff like the OP's question, perhaps trying to learn more about networking, and then come to these forums to find answers.

So, there's possibly some benefit to others, beyond the OP, even for specific answer for the OP's described equipment and issue.

I also agree, in general, often typical multi-year replies offer little, and are actually a nuisance to see pop up into currently active threads (don't get me going on the SPAM variants), but in this specific case, IMO, I believe Enes' reply is more positive than the typical negative of such cases.

Possibly unintended, on your part, but my impression of your initial reply was for such old posts, it's NEVER worth replying to such.  Again, likely you didn't actually want to convey "never", but that's my impression.  I'm of the opinion such replies should be made ALMOST never.  ; )

One reason I've also replied, is, I understand many take very seriously replies from VIPs.  So, I decided posting an alternative opinion to NEVER (whether intended or not) might be of benefit to Enes and/or others for additional suggestions for doing, or not, similar replies.

[Giuseppe Larosa]

Hello @Enes Simnica ,

for your information the user @thisisshanky has been  very active until 2009 or something like that . He has been one of the first guys to be interviewed

Hope to help

Giuseppe

[Enes Simnica]

First of all, thank you all for your participation. While I understand the question is quite old (which I absolutely don’t care), I came across it while searching for something relevant and decided to share an answer. In my opinion, the age of the question doesn't diminish its value. It might still be helpful to someone out there, and that’s what matters most. So, let’s not make a big deal out of this. Chill (LOL), everyone—knowledge is timeless, and you never know who might benefit from this information .

And if it is against the rules of the Cisco community, just let me know. 

Respect!

But, I absolutely understand each and everyone's point here (it makes sense).

P.S. More Cisco?!

-Enes

[marce1000]

         - Cisco forever ! (LOL!)

 M.

[Enes Simnica]

Each morning when @marce1000 Marce wakes up and looks into the mirror, he always says, 'Why am I so brilliant?' The mirror then always responds to him with, 'The only thing that exceeds your brilliance is your beauty!

lool

Such an amazing description you have there, man (SICK)!

[marce1000]

 @Enes Simnica  - I always try to remain humble...

 M.

[Joseph W. Doherty]

"knowledge is timeless"

Agreed!

"the age of the question doesn't diminish its value"

Disagree!  Age often impacts relevance and/or value.

E.g. How do you control write protection on a mag tape?  How do you hand decode an IBM 80 column punched card encoded in EBCDIC?

Answers to the prior two questions wouldn't generally be considered as valuable to know now as the were 60 years ago.  Laugh, on the other hand, if someone really needed to know the answers today, such information might be considered invaluable.

So, again, agree knowledge is timeless but its value varies, and with technology, much of its value diminishes as it ages due to evolution of technology.

For example, my papa, don't know why, once told me the proper way (to avoid having your hand broken) to hand crank a Model T.  If I ever need to hand crank a Model T, haven't so far, it will then be valuable knowledge.  ; )