Page 59 of 63 FirstFirst ... 9495051525354555657585960616263 LastLast
Results 581 to 590 of 623
  1. #581
    Service Manager 2,500+ Posts
    Need some advice on learning networking

    BillyCarpenter's Avatar
    Join Date
    Aug 2020
    Location
    Long Beach, Mississippi
    Posts
    4,138
    Rep Power
    142

    Re: Need some advice on learning networking

    I finally got back around to setting up DHCP services on intervlans. This was no easy task for a beginner like myself. First I had to set up the vlans. Then I had to set up intervlans and make sure the PC's could all communicate. Than I had to set up the DCHP Server. Getting the DHCP server to work on VLAN 10 was simple because I made the DHCP server part of VLAN 10. Now I had to get the server to work on VLAN 20. Just to make it a little harder on myself, I used a multi-layer switch with a built in router....which I had never used before.


    Let me just cut this short. The name of the game in this scenario is sub interfaces, sub interfaces, and sub interfaces. Did I mention sub interfaces? Once I got all of the sub interfaces set up the only thing left to do was set up "IP Helper" which is a relay back to the DHCP server for VLAN 20.

    I'm tired and my head hurts. That's it for today.

  2. #582
    Trusted Tech 50+ Posts
    Need some advice on learning networking


    Join Date
    Oct 2010
    Posts
    94
    Rep Power
    22

    Re: Need some advice on learning networking

    Quote Originally Posted by BillyCarpenter View Post
    Now let's talk about routers and the role they play in INTER-VLANS.


    Keep in mind that VLANS are at the switch level (layer 2) and they are separate networks that can't communicate with each other. But what if you want to communicate between the different VLANS? In order to do this we need a router. Unlike switches, routers care about IP addresses (layer 3). It's important to keep this in mind before I explain how inter-vlans are possible....


    ....If we have a PC on VLAN 1 it may have an IP address of 192.168.10.2. On VLAN 2 we may have another PC with the IP address of 192.168.20.2. In other words, PC's on different VLAN can't have the same mask, or subnet. That would kind of defeat the purpose.

    Anyway, the PC sends the packet to the switch, the switch looks in it's VLAN table and has no way of sending the packet between 2 different VLANs. What happens next is the packet is sent to the router. Keep in mind that the path between the switch and router is connected by a trunk line thusthe VLAN tag (encapsulation 802.1Q) hasn't been stripped away and is still present. Once the packet reaches the router, it has it's own table that it looks at. This table is a different from the table found at the switch. This table binds the VLAN to an IP Address.

    I'll admit that's a little confusing and took me a while to grasp.
    what subnet mask would you use for 192.168.10.2 and 192.168.20.2? If you used a 255.255.255.0 would they be able to communicate with each other?

  3. #583
    Service Manager 2,500+ Posts
    Need some advice on learning networking

    BillyCarpenter's Avatar
    Join Date
    Aug 2020
    Location
    Long Beach, Mississippi
    Posts
    4,138
    Rep Power
    142

    Re: Need some advice on learning networking

    Quote Originally Posted by adecanmin View Post
    what subnet mask would you use for 192.168.10.2 and 192.168.20.2? If you used a 255.255.255.0 would they be able to communicate with each other?

    To be perfectly honest, I may have used some wrong terminology. This was what I was trying to say:


    Take IP address 192.168.10.2 with a 24 bit subnet.

    The red portion represents the network portion of the address and the black indicates the host. You can't have the same network portion for two different VLANS as VLANS are, by design, separate networks. Sorry for the confusion.

  4. #584
    Service Manager 2,500+ Posts
    Need some advice on learning networking

    BillyCarpenter's Avatar
    Join Date
    Aug 2020
    Location
    Long Beach, Mississippi
    Posts
    4,138
    Rep Power
    142

    Re: Need some advice on learning networking

    By the way, on several videos that i watched, they kept referring to the network portion of the IP address as the "mask." Is that not correct?

  5. #585
    Retired 10,000+ Posts slimslob's Avatar
    Join Date
    May 2013
    Location
    Bakersfield, CA
    Posts
    14,089
    Rep Power
    374

    Re: Need some advice on learning networking

    Quote Originally Posted by adecanmin View Post
    what subnet mask would you use for 192.168.10.2 and 192.168.20.2? If you used a 255.255.255.0 would they be able to communicate with each other?
    192.168.10.2 and 192.168.20.2 are just IP addresses. A subnet mask of 255.255.0.0 will allow communicating with every device on every subnet of 192.168. Changing the value of the third octet would restrict the number of subnets and changing the value of the fourth octet will restrict the devices on each subnet. I would have to look up the proper tables to tell you what each value would yield and I don't feel like doing so right now.

  6. #586
    Service Manager 10,000+ Posts
    Need some advice on learning networking

    Phil B.'s Avatar
    Join Date
    Jul 2016
    Location
    Raleigh NC
    Posts
    12,378
    Rep Power
    311

    Re: Need some advice on learning networking

    Quote Originally Posted by slimslob View Post
    192.168.10.2 and 192.168.20.2 are just IP addresses. A subnet mask of 255.255.0.0 will allow communicating with every device on every subnet of 192.168. Changing the value of the third octet would restrict the number of subnets and changing the value of the fourth octet will restrict the devices on each subnet. I would have to look up the proper tables to tell you what each value would yield and I don't feel like doing so right now.
    He can look all that on the net.
    I like Duck Duck Go and Yahoo search engines.
    Search network IP/sub net addressing or some such.

    Sent from my SM-G960U using Tapatalk

  7. #587
    Service Manager 2,500+ Posts
    Need some advice on learning networking

    BillyCarpenter's Avatar
    Join Date
    Aug 2020
    Location
    Long Beach, Mississippi
    Posts
    4,138
    Rep Power
    142

    Re: Need some advice on learning networking

    Quote Originally Posted by BillyCarpenter View Post
    For 2 days I've been trying to get back to my practice lab on sending DHCP addresses across inter-vlans but because I had had weak areas in my knowledge, I had to go back and fill those gaps. This is a lot of information to take in at one sitting. Take my word for this....you don't want any gaps in your understanding of networking because it will come back to bite you. I learned that the hard way. Don't repeat my mistakes if you're trying to learn networking. No detail is unimportant.

    There's one more gap that I had to fill before I went back to my practice lab on sending DHCP across inter-vlans and that's DORA.


    What is DORA? I'm glad you asked.


    DHCP Dora process is handled by a SERVER called DHCP SERVER that dynamically distributes network configuration parameters, such as IP Addresses, gateways, ect. for clients. It is a standardized network protocol used on INTERNET PROTOCOL in the network.

    Sound complicated? It's not. Here's how it works.


    First the client PC sends out a Discovery Broadcast across the network to see if a DHCP Server is on the network.

    Next the DHCP server sends back an Offer that includes the IP address, gateway, ect.

    Next the client PC sends back a Request saying that he will take the IP address.

    Next the DHCP server sends back an Acknowledgement saying "okay, you I'll make a note of your IP address and you can have this IP address for 4-days (or whatever)...known as the lease time.


    Client -------->
    Discover
    ......................Offer<-----------Server -
    Client --------> Request
    ......................Ack<-------------Server



    I'll explain why these 4 packets are important in a later post.
    I said I would explain why DORA is important.

    This is a real problem that I run into and the reason I had to learn how DORA worked.

    I had 2 networks. One network was divided by Router 1 and the other network was divided by Router 2. I had the DHCP server on network 1 and 2 PC's on Network 2. From Network 2 I could ping the DHCP server on the other network but DHCP would not work. Ever.


    It didn't make sense. I could ping the DHCP server that was on the other network. Anyone know why it wouldn't work?



    Answer: the first letter in DORA stands for DISCOVERY and that's a "broadcast signal. Routers do not like broadcast signals and will drop them every time thus it will never reach the DHCP server.

  8. #588
    Service Manager 2,500+ Posts
    Need some advice on learning networking

    BillyCarpenter's Avatar
    Join Date
    Aug 2020
    Location
    Long Beach, Mississippi
    Posts
    4,138
    Rep Power
    142

    Re: Need some advice on learning networking

    I can't believe I'm about to say this but I'm thinking of getting my CCNA. I've checked into it. I can do an online course in a live classroom setting. It's a 180 day course. The cost is around $1000.00.

    I looked at some of the practice labs that I will have to learn. I've already done a lot of them.


    With all of that being said, I have absolutely no plan of networking for a living. I don't even know why I'm considering it other than I've become very interested in networking and I find it fascinating. And I consider it a challenge.

    Also, I'd like to have some structure learning networking as I feel like I'm kind of all of the place.


    Good idea? Bad idea? Any advice?


    Thanks.


    PS - If I decide to do this it will be a few months from now. I need to learn a little more before I take that step.

  9. #589
    Retired 10,000+ Posts slimslob's Avatar
    Join Date
    May 2013
    Location
    Bakersfield, CA
    Posts
    14,089
    Rep Power
    374

    Re: Need some advice on learning networking

    Quote Originally Posted by BillyCarpenter View Post
    I can't believe I'm about to say this but I'm thinking of getting my CCNA. I've checked into it. I can do an online course in a live classroom setting. It's a 180 day course. The cost is around $1000.00.
    Does that cost include the price of taking the certification test or is that still extra?

  10. #590
    Service Manager 2,500+ Posts
    Need some advice on learning networking

    BillyCarpenter's Avatar
    Join Date
    Aug 2020
    Location
    Long Beach, Mississippi
    Posts
    4,138
    Rep Power
    142

    Re: Need some advice on learning networking

    Quote Originally Posted by slimslob View Post
    Does that cost include the price of taking the certification test or is that still extra?

    The exam is extra.

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Get the Android App
click or scan for the Copytechnet Mobile App

-= -= -= -= -=


IDrive Remote Backup

Lunarpages Internet Solutions

Advertise on Copytechnet

Your Link Here