Nat overload translation

[lucad7846]

Hi 

I have configured nat with overload created the access list and all. 

Now I am struggling to create a translation that would allow the whole 192.168.1.0 network to be translated to the inside global address 209.165.200.18

I understand how to do the translation when is a 1-to-1 address translation but I can't figure out the syntax to translate the whole network. Should a nat pool be implemented in this scenario? 

Any suggestion would be much appreciated. 

Many thanks in advance 

[MHM Cisco World · Accepted solution]

all config is right except you forget add default GW in Server.

[lucad7846]

Hi thanks so much. I completely forgot about. Thanks for the suggestion. Cheers

[Georg Pauwen · Accepted solution]

Hello,

you also need a default route:

ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/1

Attached the revised, working file...

[lucad7846]

Hi Georg. 

Thanks so very much for that. 

One thing I still don't get though. I don't think I have specified what the inside local and inside global addresses are. Isn't this a requirement for the all scenario to work? I'm asking cause I'm trying to understand how it all works. Many thanks

[Martin L]

This is called Source NAT mapping (ip nat inside) and use to translate many internal local LAN Private IPs into Public IP in order to get to the Internet. Due to shortage of Public IPs, NAT and PAT was born.  PAT is like NAT but adds not used TCP/UDP ports to single IP.  Note that those Private IP range are not routable on the Internet; ISP blocks them by default. Hence, those must be translated (mapped) to Public IP or Public range given to you by ISP. 

Best way to learn and remember this is practice with Private/Public IP scheme; that way is less confusing.  Cisco uses the terms:  inside local =  my private IP addresses while inside global = my public IPs.   Note inside is me while destination server like www is Outside (from my perspective).  I should have example lab for this nat thing; will attach once file is found. 

I recommend W. Odom's CCNA OCG book which explains NAT/PAT very well.  Book comes with colorful pictures and lots of tables;  Attach is Wendell;s explanation of terms inside local and inside global addresses (CCNA 200-301 Official Cert Guide, Volume 2, Odom Wendell, 2020 Cisco Press)

Regards, ML

[lucad7846]

Hi Martin 

Thank you very much for your help. 

Funnily enough I had to configure PAT for one of my assignments today. The inside local and global can be confusing indeed but I think I got it now. Thanks for sharing the attachment.

@Martin LOn a slightly different note what would be the best way to prepare for the CCNA 300-201 certification?

Many thanks in advance

Cheers

Luca

[Martin L]

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@Martin LOn a slightly different note what would be the best way to prepare for the CCNA 300-201 certification?

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Mentioned above book set by Wendell Odom, CCNA 200-301 Official Cert Guide, is a must have !  Read couple times; make sure you understand it well. Plus some labs and videos would be nice to get different perspective for subject mentioned in the book.  There are some Free videos on youtube that could help you; I am sure you can find free labs for PT as well.  Otherwise, from paid stuff, Recently praised Udemy CCNA video tanning course comes with both videos and labs made for PT. 

Visit Cisco Learning network and Get blueprint of CCNA topics; Also they have discussion forum you can check for latest news, pass/fail info, etc. They also have a store with CCNA course. 

Regards, ML

[lucad7846]

Hi thanks for the info. Ops silly me

my bad I thought the book you suggested was just about NAT and PAT. CCNA 200-301 Official Cert Guide... How did I miss it?! 

@Martin L I looked up the book and I found one online.CCNA 200-301 Official Cert Guide volume 1. Is there more than a volume or this one is enough to prepare for the CCNA cert? Screenshot attached 

Many thanks for the info.

Cheers

[Martin L]

no, vol 1 in not enough, need vol 2, there should be 2 books or set, look at bundle option. Also, if books include labs and testing software, that's good deal. Those used to be sold separately,  maybe now they are included 

Side note, Labor Day holiday is coming up, there usually have discounts 

Regards , ML

[lucad7846]

Hi Martin thanks so much.

I am not entirely sure where you are. I am in Australia and Labor Day is not until the first weekend in October. 

It doesn't matter though, I think it's a good investment even if I have to pay full price. 

Cheers 

[Martin L]

Right, I am thinking American and/or US based company, so maybe Holidays follow them even overseas. ... not sure.

Also check this Best Value Purchase book+ ebook at  Ciscopress.com and www.informit.com 

https://www.ciscopress.com/store/ccna-200-301-official-cert-guide-library-9781587147142

[lucad7846]

Gotcha yeah you're probably right. 

Thanks for the link. I'll check it out. 

Thanks so much for all the suggestions. 

Cheers