Re: subnet vs. Vlan
[EMAIL PROTECTED] wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... I beg to differ on this one. I'm currently dealing with a network that has 4 VLANs. Two of those VLANs use multiple subnets. the only thing you need to do to make another subnet work on a VLAN is a secondary IP on the router interface for that VLAN. Remember - VLANs are layer 2 (MAC address), not Layer 3 (IP address). The only entity that cares what subnet a node belongs to is the router. Well, that and the IP hosts themselves =) Walker Traylor To: [EMAIL PROTECTED] wtraylor@ciscc: co.com Subject: Re: subnet vs. Vlan Sent by: nobody@groups tudy.com 07/20/00 04:20 PM Please respond to Walker Traylor You must use a router between any networks, even if they are on the same VLAN. You do not need a router to merely connect VLANS if they are on the same network. However, you could just make them just one VLAN in that case. --Walker jeongwoo park wrote: HI all I have a question. Cisco recommends that there be one-to-one relationship between ip subnets and Vlans. When the number of devices on a Vlan exceeds the number of host ip addresses per configured subnet, more than one subnet can exit on a Vlan. Having said that, my question; There are two subnets in a Vlan. Do we need a router to interconnect these two subnets? I know that we need a router to interconnect two different Vlans. In addtion to that, can more than one vlan exist on a subnet? if so, do we still need a router to interconnect different vlans even if there are in a same subnet? thanks jeongwoo ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: subnet vs. Vlan
The simple way to think about it is this: VLAN = Subnet. If you do it any other way you are defeating the purpose of using VLANs (except , of course, for the earlier example I gave). Tony --- Unfortunately that isn't the case anymore. If you look at what companies like Extreme are doing in the MAN, they are creating vlan's within the same IP subnet to provide transparant LAN services across an IP network. The technnology is called a vMAN - see: http://www.extremenetworks.com/technology/whitepapers/vman.asp?MakeChange=No irwin ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: subnet vs. Vlan
Your correct that the "only thing you need to do to make another subnet work on a VLAN is a secondary IP on the router". By doing this you are allowing the router to forward packets between devices on the separate subnets. i.e. you need the router to perform inter-subnet forwarding, which is what the original question was. Without configuring secondaries on the router, the router cannot forward between the 2 different subnets and the devices on the respective subnets cannot talk to one another. The original question was whether devices on the same VLAN can talk to each other without a router if their IP addresses are in different subnets, and the answer is no. You have to appropriately configure the router with secondary IP addresses to allow it to forward packets between the subnets. -Kent -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of [EMAIL PROTECTED] Sent: Friday, July 21, 2000 9:13 AM To: Walker Traylor Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: Re: subnet vs. Vlan I beg to differ on this one. I'm currently dealing with a network that has 4 VLANs. Two of those VLANs use multiple subnets. the only thing you need to do to make another subnet work on a VLAN is a secondary IP on the router interface for that VLAN. Remember - VLANs are layer 2 (MAC address), not Layer 3 (IP address). The only entity that cares what subnet a node belongs to is the router. Karen E Young Network Engineer ELF Technologies, Inc [EMAIL PROTECTED] Desk: 206-770-4035 Pager: 206-994-4514 Walker Traylor To: [EMAIL PROTECTED] wtraylor@ciscc: co.com Subject: Re: subnet vs. Vlan Sent by: nobody@groups tudy.com 07/20/00 04:20 PM Please respond to Walker Traylor You must use a router between any networks, even if they are on the same VLAN. You do not need a router to merely connect VLANS if they are on the same network. However, you could just make them just one VLAN in that case. --Walker jeongwoo park wrote: HI all I have a question. Cisco recommends that there be one-to-one relationship between ip subnets and Vlans. When the number of devices on a Vlan exceeds the number of host ip addresses per configured subnet, more than one subnet can exit on a Vlan. Having said that, my question; There are two subnets in a Vlan. Do we need a router to interconnect these two subnets? I know that we need a router to interconnect two different Vlans. In addtion to that, can more than one vlan exist on a subnet? if so, do we still need a router to interconnect different vlans even if there are in a same subnet? thanks jeongwoo __ Do You Yahoo!? Get Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] --- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: subnet vs. Vlan
Karen, I think I was being unclear. I think we meant the same thing. " the only thing you need to do to make another subnet work on a VLAN is a secondary IP on the router interface for that VLAN." A layer 3 device (router) is neccessary to connect different subnets, regardless of whether they are on the same physical network (or in the case of VLANS, "virtual physical network"...I'll just call them layer 2 networks.) --Walker [EMAIL PROTECTED] wrote: I beg to differ on this one. I'm currently dealing with a network that has 4 VLANs. Two of those VLANs use multiple subnets. the only thing you need to do to make another subnet work on a VLAN is a secondary IP on the router interface for that VLAN. Remember - VLANs are layer 2 (MAC address), not Layer 3 (IP address). The only entity that cares what subnet a node belongs to is the router. Karen E Young Network Engineer ELF Technologies, Inc [EMAIL PROTECTED] Desk: 206-770-4035 Pager: 206-994-4514 Walker Traylor To: [EMAIL PROTECTED] wtraylor@ciscc: co.com Subject: Re: subnet vs. Vlan Sent by: nobody@groups tudy.com 07/20/00 04:20 PM Please respond to Walker Traylor You must use a router between any networks, even if they are on the same VLAN. You do not need a router to merely connect VLANS if they are on the same network. However, you could just make them just one VLAN in that case. --Walker jeongwoo park wrote: HI all I have a question. Cisco recommends that there be one-to-one relationship between ip subnets and Vlans. When the number of devices on a Vlan exceeds the number of host ip addresses per configured subnet, more than one subnet can exit on a Vlan. Having said that, my question; There are two subnets in a Vlan. Do we need a router to interconnect these two subnets? I know that we need a router to interconnect two different Vlans. In addtion to that, can more than one vlan exist on a subnet? if so, do we still need a router to interconnect different vlans even if there are in a same subnet? thanks jeongwoo __ Do You Yahoo!? Get Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] --- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
subnet vs. Vlan
HI all I have a question. Cisco recommends that there be one-to-one relationship between ip subnets and Vlans. When the number of devices on a Vlan exceeds the number of host ip addresses per configured subnet, more than one subnet can exit on a Vlan. Having said that, my question; There are two subnets in a Vlan. Do we need a router to interconnect these two subnets? I know that we need a router to interconnect two different Vlans. In addtion to that, can more than one vlan exist on a subnet? if so, do we still need a router to interconnect different vlans even if there are in a same subnet? thanks jeongwoo __ Do You Yahoo!? Get Yahoo! Mail Free email you can access from anywhere! http://mail.yahoo.com/ ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
subnet vs. Vlan
HI all I have a question. Cisco recommends that there be one-to-one relationship between ip subnets and Vlans. When the number of devices on a Vlan exceeds the number of host ip addresses per configured subnet, more than one subnet can exit on a Vlan. Having said that, my question; There are two subnets in a Vlan. Do we need a router to interconnect these two subnets? I know that we need a router to interconnect two different Vlans. In addtion to that, can more than one vlan exist on a subnet? if so, do we still need a router to interconnect different vlans even if there are in a same subnet? thanks jeongwoo __ Do You Yahoo!? Get Yahoo! Mail Free email you can access from anywhere! http://mail.yahoo.com/ ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: subnet vs. Vlan
What will probably happen is that not all hosts will get broadcasts. jeongwoo park wrote: HI all I have a question. Cisco recommends that there be one-to-one relationship between ip subnets and Vlans. When the number of devices on a Vlan exceeds the number of host ip addresses per configured subnet, more than one subnet can exit on a Vlan. Having said that, my question; There are two subnets in a Vlan. Do we need a router to interconnect these two subnets? I know that we need a router to interconnect two different Vlans. In addtion to that, can more than one vlan exist on a subnet? if so, do we still need a router to interconnect different vlans even if there are in a same subnet? thanks jeongwoo __ Do You Yahoo!? Get Yahoo! Mail Free email you can access from anywhere! http://mail.yahoo.com/ ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] --- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: subnet vs. Vlan
You must use a router between any networks, even if they are on the same VLAN. You do not need a router to merely connect VLANS if they are on the same network. However, you could just make them just one VLAN in that case. --Walker jeongwoo park wrote: HI all I have a question. Cisco recommends that there be one-to-one relationship between ip subnets and Vlans. When the number of devices on a Vlan exceeds the number of host ip addresses per configured subnet, more than one subnet can exit on a Vlan. Having said that, my question; There are two subnets in a Vlan. Do we need a router to interconnect these two subnets? I know that we need a router to interconnect two different Vlans. In addtion to that, can more than one vlan exist on a subnet? if so, do we still need a router to interconnect different vlans even if there are in a same subnet? thanks jeongwoo __ Do You Yahoo!? Get Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] --- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
