ACL Placement: Closer to the Source or Destination? -- Access Control Lists (ACLs) -- Part 8 of 8

[@firewire259]

I struggled with understanding this concept until I came across this video. Excellent!!!

[@PracticalNetworking]

Awesome, glad these helped! If you're willing... Could you do me a favor? Do you mind sharing this series on Linked In, Reddit, Twitter, Facebook, or any other social media you use? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .

[@markneilandit8406]

You are the only one who made me understand ACL completely even after watching so many popular cisco tutorial and paid videos/books. Please keep em coming including ccnp/encor topics. Subscribed!

[@PracticalNetworking]

Thanks for the support, Mark! Glad this series helped it click for you.

[@sandravaldez9088]

In just a few minutes of your time, I was able to grasp concepts that had previously eluded me for hours. Thank you, Mr. Practical

[@2012mrmoh]

Man you have the knowledge. Well done please continue.

[@PracticalNetworking]

Thank you =). Could you do me a favor? Do you mind sharing this video on Linked In, Reddit, Twitter, Facebook, or any other social media you use? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .

[@alexandrucozma6603]

I hope my network professor watches this video and learns how the lecture should be. So detailed and easy explained! Thank you so much!!

[@microsoul669]

I will echo other comments and say thank you: I struggled with ACLs (especially where to apply them) and your videos made it crystal clear. Great work!

[@PracticalNetworking]

Glad you learned a lot from this series =). This series doesn't seem to do well with the KZbin algorithm.... if you're willing, please consider sharing this resource with others. Cheers.

[@bobhamilton6760]

Yet another terrific series... Thank you!

[@PracticalNetworking]

You're welcome, Bob. Glad you liked it !

[@Mohammadjulfikar7187]

The entire series is just outstanding!

[@PracticalNetworking]

Glad you think so, Mohammad. Please spread the word about this content =)

[@Mohammadjulfikar7187]

@@PracticalNetworking Sure sir, I will circulate the content and spread the words about this wonderful channel.

[@irappaaddi1820]

Thanks for the series.. crystal clear with ACL concept.

[@PracticalNetworking]

Cheers, Irappa =)

[@nicolasalarie7146]

Thank you for this series the way of explain thing make it so simple to understand compared to the dry cisco material with 50 sentences to explain something that should only take 3 sentences.

[@SEAhawkstwelfthman]

Clear, concise, and perfectly explained. Thank you sir.

[@PracticalNetworking]

Thank you. Glad you enjoyed the series!

[@creumakuzola4227]

Excellent series, sir. Thank u so much for this, it helps me a lot

[@yonzonful]

Good Job, as the whole ACL Servies have been explained in a very simple way but effectively. Please keep posting. thank you.

[@PracticalNetworking]

Thank you. Glad you enjoyed the series =)

[@BILLKUBA]

Wow so clear and concise, I subscribed within a few minutes into the video... Can't fault the delivery of this content

[@PracticalNetworking]

Thank you for the kind words, and for your support =). Oddly, this ACL series hasn't received nearly as much attention as some of my other content. Would you be willing to help me out by referring people to this content public forums or CCNA groups?

[@StylistecS]

Thank you for this series I had a major confusion look on my face about ACL's, but I understand them a bit better after this series.

[@temeraire237]

Thank you for the video ! You did explained it well and it was just what i needed for my exam.

[@scorpio_1312]

Thank you Ed for this series! Now I'm ready for a few labs in the command line to mater this topic.

[@PracticalNetworking]

Excellent =) Glad you feel ready for labs!

[@joedoe27]

thank you for making it cristal clear ,i did have problems understanding this part.Thank You!

[@crusiour8912]

Loved it brother. You are a saviour of the masses.

[@PracticalNetworking]

[@sameergori2127]

series was fun and informative. Moreover, simple to understand, THANK YOU!!!!

[@PracticalNetworking]

Glad it helped, Sameer =)

[@ketanbhatt9243]

Awesome Series on ACL

[@PracticalNetworking]

Thank you, Ketan =)

[@holdthissl]

This was a perfect video series thank you so much!

[@PracticalNetworking]

You're very welcome =)

[@tg1982]

Great series! I was able to follow the concepts you are transmitting and the drawings were pretty clear. Awesome job! Thanks!

[@PracticalNetworking]

You're welcome =)

[@krishnasubedi2685]

Thanks a lot you made my day more easier.

[@PracticalNetworking]

Glad to help, Krishna! Thank you for supporting the channel!

[@rafay1708]

Thank you so much for making such useful and perfect Videos.

[@PracticalNetworking]

You're welcome, Rafay. =)

[@BekoIQ]

#1 about ACL thanks dear

[@PracticalNetworking]

Most welcome 😊

[@joelgeorge4197]

Short and precise!

[@PracticalNetworking]

Glad you enjoyed it =)

[@mrd4233]

A big thanks for the demo!

[@PracticalNetworking]

Certainly =)

[@mosesa.4336]

Awesome series

[@PracticalNetworking]

Thank you.=)

[@scottspa74]

I'm loving all your videos. I was hoping you might dig in a bit more to the in vs. out concept when I saw you had an ACL series. That is what I struggled with most in this curriculum (I took all 3 quarters of the Cisco curriculum at Edmonds CC). In the in/out decision, the perspective always throws me. It seem that if a packet is going in and intfc, it is also going out an intfc. It always trips me up. If you're considering more videos, I'd love to hear your explanation about in/out. Your videos are excellently balanced between concepts, commands, and visuals, you really have a great formula. Most other instructors I watch lean way too heavily on one, at the expense of the other(s). Thanks for doing these.

[@PracticalNetworking]

You're welcome again Scott. Glad you're enjoying my content! I discuss the "in/out" distinction in Video 1 of the ACL series. I'd recommend giving that a re-watch. At the end of the day it's just choosing where precisely you want to filter for traffic. (coming in one interface, going out another interface, etc...). You could also filter in "both" places, but that is a bit redundant. Beyond that, feel free to ask more specific questions in my discord: pracnet.net/discord. Cheers!

[@sevinjabdullayeva2239]

Great series! Thank you for the videos! :)

[@PracticalNetworking]

Glad you enjoyed it, Sevinj. Cheers !

[@nidhinyou]

Very clearly explained...

[@PracticalNetworking]

Thank you, Nidhin =).

[@nicklee2841]

Awesome videos! Thanks Ed.

[@PracticalNetworking]

You're welcome, Nick. If you are willing... Could you do me a favor? Do you mind sharing this video series on Linked In, Reddit, Twitter, Facebook, or any other social media you use? Despite the effort, this series didn't quite attract as much attention as I had hoped it would.

[@amiraazmy6701]

Thank you so much, Playlist is really good and complete source for ACLs, it has everything theory & Labs ! Well done, organized & well explained !!

[@amiraazmy6701]

Any chance for another video on famous network protocols ? like : DNS/DHCP/ARP/ICMP/FTP / HTTPS & HTTP/STMP/POP3/SYSlog/SNMP/Telnet/SSH .. quick video how they work & how they affect/change packet

[@PracticalNetworking]

Glad you liked it =). I did a video and article series on ARP: kzbin.info/www/bejne/h4HMZoGsrcaiqdk www.practicalnetworking.net/series/arp/address-resolution-protocol/ And I'm currently building (what I believe) to be the best class on SSL/HTTPS. There is an early access program if you're interested: www.practicalnetworking.net/announcement/looking-for-reviewers-for-my-tls-ssl-deep-dive-course/

[@burimshala4377]

Thank you very much! You are doing great videos with your explanations!

[@PracticalNetworking]

Glad you like them, Burim. Thank you for your support.

[@merrellsegars1004]

My thoughts. Because a Standard ACL only defines Source, placement is closest to the missing explicative, the Destination where the filter must be applied. Extended and IPv6 have the full path, we apply the filter closest to the Source to reduce traffic most. Otherwise, extra processing cycles are wasted. "Should drop packets as early as possible" when we have both SRC and DST. Got it!

[@PracticalNetworking]

You're reasoning is on point. Yes, since the Standard ACL is "missing" the Destination definition, placing it closer to _that_ destination helps reduce the unrestrained blocking. Good way of thinking about it.

[@esesmac]

Great content! Keep going !

[@PracticalNetworking]

Cheers Ernesto. Glad you're enjoying this series as well =)

[@Candythrills]

mind blowing content bro !! hats off

[@PracticalNetworking]

Thank you =). Could you do me a favor? Do you mind sharing this video on Linked In, Reddit, Facebook, or any other social media you use? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .

[@MDSGI]

Great Tutorial!!!

[@PracticalNetworking]

Thank you, Jeff.

[@onemoremood2761]

DONT DELETE THESE VIDEOS!!!! I am in an intro to networking course at my CC and this has helped me so much in my studies and understanding the class text. Thank you so much for taking the time to do this!

[@PracticalNetworking]

You're welcome. And don't worry, I have no plans to delete these videos =). Please feel free to share the link to the landing page for all the videos with your class mates: www.practicalnetworking.net/series/access-lists/acls/

[@onemoremood2761]

@@PracticalNetworking already did! thanks for the reply and if you can do a video series and expand on NAT and PAT that would be awesome!

[@PracticalNetworking]

@@onemoremood2761 I wrote an article series discussing NAT and PAT here: www.practicalnetworking.net/series/nat/nat/ I've also published three video courses on NAT/PAT if you prefer videos here: classes.pracnet.net/courses/network-address-translation Hope you enjoy!

[@oridayan9547]

thank you so much for arranging the data in my brain with your clear explanations. btw, below the video, the link to part 8 refers to part 1...

[@PracticalNetworking]

Glad you enjoyed it! Thanks for pointing out the typo as well!

[@supersonichuman]

Thank you so much for this video!

[@sheru9229]

Amazing explanation...thanks alot for your hard work.

[@PracticalNetworking]

Thank you. You're very welcome =)

[@coldane2]

Great series, really helped me understand ACL's, I did however have to turn the playback speed to 0,75..but maybe thats just me, non-native English speaker and all.

[@PracticalNetworking]

Glad you enjoyed the series =). That's the beauty of KZbin, you can speed up or slow the playback as necessary. Cheers!

[@akme2d]

Amazing. Thank you

[@PracticalNetworking]

You're welcome!

[@leothalion3983]

Thank you so much!!!!!

[@PracticalNetworking]

You're welcome!

[@muhammadajmalsharif4562]

Awesome stuff thx bud

[@PracticalNetworking]

You're welcome, Ajmal!

[@jdrysdale10]

You are the best!

[@reeteshhurkhoo9231]

Thank you very much sir.

[@idealnun6418]

Great video seris thank you

[@Tankovich777]

Many thanks

[@hunterxrick]

Awesome series for understanding ACL's as a whole, thank you !

[@PracticalNetworking]

You're very welcome!

[@riadhtemzi9554]

omg ur the best I have never understand acl like this time thanks a lot +1 sub from me

[@PracticalNetworking]

Glad you enjoyed it, Riadh. Happy to help you with your understanding of ACLs =)

[@diligenzz2032]

great content!

[@PracticalNetworking]

Thanks =)

[@cybersecurity90]

Perfect (y).

[@PracticalNetworking]

Thanks, Qasim =)

[@JudeMuntadher]

Thank you so much for the great effort. Just out of curiosity, do you use power point for presentation or something else. I am trying to learn the stylus vanish mode you are using but can't figure it out. Thanks again.

[@PracticalNetworking]

You're welcome! The slides are Powerpoint. The annotation/drawing is IPEVO Annotator, they have a "pen" with a "disappearing ink" feature. It's great, check it out !

[@sandravaldez9088]

Dear Ed, I was wondering if you might have a "problem generator" available for practicing the creation and solving of ACLs, similar to the one you offer for subnetting practice. I've found the subnetting problem generator incredibly beneficial for honing my skills and reviewing my results. If possible, could you kindly share the link with me or consider creating such a tool? Your educational resources have been consistently outstanding, and I greatly appreciate your assistance. Thank you,

[@PracticalNetworking]

Love the idea =) Doesn't exist at the moment.

[@leonorabuenavista8153]

If we put ACL in the interface near PC-C it will prevent it from speaking to PC-A. But if I want PC-A to speak to PC-C, will it be possible? I mean is it possible for a 1 way communication? Thanks.

[@PracticalNetworking]

Yes. But 1-way communication is rarely helpful in Networking. Consider every TCP protocol requires the completion of a handshake, which means bidirectional communication must exist before any data will actually be sent.

[@kkudayippu]

nice video ..could you please make a tutorial video for VPN

[@PracticalNetworking]

It's on the list =)

[@kkudayippu]

@@PracticalNetworking Thank yo Bozz

[@EyeIn_The_Sky]

Would you recommend that the most specific in terms of subnet mask length Access control List entry (ACE) should be placed at the top of the ACL otherwise the host or network you are trying to match will be caught by more generic rules placed above it?

[@PracticalNetworking]

I wouldn't go so far as to say that is "always" what you should do. It is a "generally" good strategy, but not an explicit rule you should always follow. There are times when the less specific rules must take priority. For instance, a lot of edge routers have ACLs on their external interfaces preventing RFC 1918 traffic from coming in. These rules would include a /8, /12, and /16 mask, but ought to take precedence over whatever "smaller" permits might exist later. The best solution is to really understand the implication of priority and access-lists, and then build an ACL policy which best matches the requirements and policies of your specific location.

[@AmirHussain-ht4eq]

Very good explanation 👍

[@PracticalNetworking]

Thank you, Amir.

[@martinking4615]

Amazing! it was very informative and helpful ...God bless ya

[@PracticalNetworking]

Glad you enjoyed it, Martin. =)

[@Jahisthereal]

had to suscribe this is just the best lesson i've seen on acl yet, thanks !

[@PracticalNetworking]

Thank you for the kind words and your support =)

[@jyotirmoy8082]

Very well described.

[@PracticalNetworking]

Thank you =)

[@nikolaandric8148]

perfect

[@Zenandchill1111]

I just finished watching the series I learned so much. The videos you make are easy to understand and apply thank you again.

[@Flydudue25]

I needed to understand ACL for my home network and this video series is perfect. Thank you