Cisco Switching/Routing :: 3750 - LAN Switching Design
Nov 17, 2011
I have a typical LAN environment that spans across a large warehouse. I have done a lot of redesigning of the environment to satisfy the need for a disaster recover plan. I now have created a LAN with multiple v lans and must also connect all the access layer switches back to the core switch where the servers are.
I was thinking of something simple such as Port channel of 2 Gbps across the backbone and simple floating static routes . I have then moved my wan access link to a 3750 and implemented routing a CEF at each of the 3 core switches (blue). My question is more of design.
I would like to do the following architecture with the same C3750 : network X,Y,Z connected to 3750 in VRF D the 3750 uses a routed interface on subnet E for the default route in VRF D on this routed interface a BYPASS EQUIPMENT the other BYPASS EQUIPMENT interface is connected also to another routed interface on subnet E "also" this routed interface is in another VRF C with other network A and B.do you know if it will work because of 2 routed interfaces on the same IP subnet or is there a way to do that ? the only goal for me is to catch traffic from network X,Y,Z on SYN and ACK.
I'm working designing a switch system for our core/data center.
We have 5 esx hosts, 2 sans with 3 nodes each. We have voice servers, a couple of routers and a few odds and ends. There are 7 other locations aggregating into this data center via 1-2gbps fiber connections. The bandwidth usage on these links is minimal, but there is a total of about 3000 devices aggregating into the system. My main concern right now is the 3560G's are seeing many output drops, due to the small buffer size on those switches. I have been looking at couple of options to resolve this issue, including the 4948E, 4507E, and 3750X switches.
Budget being the biggest factor, I am finding that the 4507 might be out of the price range. So I was leaning towards the 4948E switches for connecting the servers and iscsi san's as the 3750X is not recommended for iscsi. Redundancy is important so I would like to have two. The second concern is that I need to aggregate the fiber connections and for that I was looking at the ME-3600X or possibly the WS-C3750X-12S-E. I'm running eigrp, so this switch would need to have full routing, as it would also serve as the core switch for the 4948E's.
So in the end I was thinking that two 4948E switches up linked to the ME-3600X which would do full routing for the fiber aggregation and any routing needed for the servers and sans.
Servers and Sans_________4948E________ME-3600X_________7 fiber connections |____________4948E_____________|
I would look at a second ME-3600X in the future for redundancy. This is the lowest cost biggest buffer solution that I could find.
I am just browsing and looking for a solution to converge my multi-vendor switched network and bring some redundancy to it as recently we managed to get a redundant links. I have a need to change core switch to Cat3750G, which has Per-V LAN-RSTP+ on board, but tests have shown that it won't be compatible with some other proprietary per-V LAN RSTP solution other vendor's switches use currently.
So, I thought maybe standard-based MSTP design might do the trick. I've made some tests and got some weird and unstable switching result. I have two topology rings with a core switch in the center. Every ring has about 10 switches, so practically network diameter may vary from 5 switches (when spanning-tree converges in the center and I have a blocking port somewhere int the middle of the ring) to about 10-11 switches (if a I have link failure on any of ports right at the core switch). I disconnected one port from core switch to eliminate a possible switching loop while I will be configuring new MSTP design. Then I started enabling MSTP on all the switches staring from core Cat3750G to MSTP, one by one, placing all switches to the same MSTP region, and placing all V LAN's to default MSTI0(CIST) cause I don't need to organize any separate MSTP instances for every V LAN or for group of V LAN s. When I turned MSTP on on 7th or 8th switch in the chain (cause I had a physical chain when I disconnected one port out of redundant ring) I got all switches "flapping", storming and flooding the network with broadcasts. Even when I had one redundant port disabled.
I have no idea what I am doing wrong. I noticed that Cat3750G has an option that defines a possible network diameter which actually automatically changes some hello, max age etc. attributes according to diameter specified. When I defined a maximum network diameter of 7, if didn't change anything: I still have hello timer of 2 sec etc. I've been wondering if the maximum network diameter has something more than just a "variable" to fine tune hello timers etc? Maybe I won't be able to use MSTP in my network which might have diameter more that 7 switches. Or maybe it was a mistake of placing all the switches to the same region and all the v LAN s to the default MSTI0 (CIST) and I should configure one MSTI per V LAN or per some group of V LANs and subdivide my switches to few MSTP regions?
We are currently designing a complete Layer 3 to the edge solution for our customers. The network design is a combination of a collapsed core (Core to access) as well as a three layer model (Core/Distro/Access) for connectivity to the Data Centre, Internet and Wireless Blocks.
The core of the network contains two 6509E switches interconnected on a Layer 3 Port channel (no VSS). Access Layer switches (3750 Stacks) connect to the core switches over p2p routed links (Collapsed core part of the design). Distribution layer switches provide connectivity to the Data centre, Internet and Wireless Blocks.(three layer model.
All IP addressing is being planned for assignment from the private RFC 1918 address block(10.0.0.0/8) for both Infrastructure and Access layer VLANs for users.
We have remote office where we have 2921 router with 6 layer 2 switches. We have few servers which need to be in specific vlan.
2921 router does not have switching engine we are using this to support VOIP.
So on 2921 router i created 6 sub interfaces for each vlan and assign them to their specfic vlans. Then I have trunk connection to switch 1. Now switch 1 connects to all other switches in the network. As our company design all layer 2 switches should be transparent mode. i tested them i can ping from one switch to all other switches.
Router vtp mode i set to transparent mode and from all switches i can ping the router sub interfaces.
We have 2 sites, each with 2 x 4506 switches which will be connected togther using an etherchannel. The switches will provide access ports for client devices and will be configured with HSRP to provide gateway redundancy. SW1 will be HSRP active.2 metro ethernet links will be installed in each site which will connect back to our HQ sites. OSPF will be used over the backbone to provide resiliency and to allow shortest path routing to each HQ and to prevent traffic over the HQ to HQ link.
The 4506 will be trunked togther with an SVI for providing OSFP adjacency.For the traffic flow from SW2 to HQ2, traffic will hit SW1 and then route back to SW2 and then to HQ2. Is this the best way to do this? Should a second link be connected between switches just for routing or should something like GLBP be used?
if the above design is acceptable how does the routers know which one is active and which one is standby ? if we need a direct connection between two routers they have to be on a seperate subnet and routers dont allow broadcasts - so how will hsrp work on routers ?
We are designing a LAN Network for ourselves.The proposed design is as follows:
4 x 2960S switches in a Stack Access-Stack-I 4 x 2960S-PoE switches in a second Stack Access-Stack-II
2 x 3750X switches in a Stack Core-Stack
Now I would like to connect it in the following manner ?First,I would like to use EtherChannel using the 10Gig LinksSecondly, I would like to use Cross-Stack EtherChanel too.I have given a graphical illustration of the connectivity Now my Qs: a) Will the 2960S supports EtherChannel using the 10G links and the 3750X too... b) Does the proposed solution will work... or It will have any problems.
QoS design problem that I have. I have a client that is deploying new 4507 series switches with SUP6Es. The client will be running lots of voice, streaming video, and video conferencing over the LAN and want to base QoS on Cisco Media net recommendations.
I need to design a new QoS policy with focus on the above media services with basic queuing for critical data services. I have read the Media net design guide and the suggested 12-class model will be too complex to start with but I have seen references to start with a 8-class model with the ability to easily migrate to 12-class in the future. The 8-class model meets all of our requirements but I need to understand how this will work with the 4507 queuing model? [URL]
I've been tasked to come up with a design to segment our internal network to reduce broadcast domain size. In addition, we are running out of DHCP available DHCP addresses. I need to have a solution that will give me more available IP's, but reduce our broadcast domain.
We are Cisco VoIP shop. Our current environment consists of dual 6509 chassis in a VSS config. We have 10 access switches that are model 3750's. Each 3750 has dual 1Gb fiber links to the VSS Core in an etherchannel configuration. We have 2 VLANS (data and voice) that spread throughout every switch. Both VLAN's have their own DHCP scope.
Our current broadcast domain is a 255.255.248.0, so we have over 2000 potential broadcast devices. Cisco recommends not having larger than 512. So my research has brought me to a design as follows:
MY DESIGN: > Have individual voice and data VLANs for each closet switch. > We have 10 closet switches so this would require 20 new vlans > With every separate VLAN we would need a different DHCP scope. > Configure 20 new DHCP scopes for the 20 new VLANs. > Each DHCP scope would have a 512 available addresses. > Enable IP Routing and configure EIGRP on the VSS Core and 3750's. > I'm tossing around the idea of have each 3750 be an EIGRP Stub. Not sure yet.
QUESTIONS: 1. How to verify what I described in my design? 2. Any alternative solution that might be less complicated than configuring Layer 3 on all my access switches? 3. Any thoughts on configuring EIGRP Stub vs. having the VSS Core do all the work? 4: Any template that I could base my 3750 config from?
Small datacenter design. My requirements and setup will be as follows Dell PowerEdge M1000E Blade Chassis (initially one full chassis)Dell Powerconnect 10GbE Blade SwitchesDell Compellent Storage Array 10Gb iSCSI with redundant controllersDell Powerconnect 7024 dedicated external storage Virtual host blade servers 2 x Cisco ASA for firewall (5525-X or similar in active-active configuration)2 x redundant routers or switches as gateway to public internet I am looking to be able to segregate customers (approximately 100) into seperate VLANs at the access layer and route them up to the Cisco ASA firewalls using Dot1Q trunking for segregation. The Cisco ASA's will perform NAT functionality and route to the redundant gateways. I then need to police each customers traffic at the gateway to limit bandwidth and perform specific traffic marking along with simply routing out to the internet.
Budget is somewhat restrictive so I am looking for the most "cost effective" devices I can use at the gateway to perform the traffic policing/marking/routing for each customer.
I'm looking for feedback and constructive criticism on our network redesign project for our company.We are currently on a 192.168.1.x/24 and running out of addresses. We are looking to move to the following design and implement VLANs as well for segregation and security. We are probably going to use a few SG300s for switches. [code]
On occasion employees are downloading large files for business purposes, at very fast speeds. This has the potential to overwhelming our Internet circuits which causes our Customers problems accessing our Web Hosting services.
Our network is comprised mostly of 2960S switches for the employees. Webservers are connected to other 2960(nonS) switches and directly into the 6509 VSS.
Customer’s traffic comes in through one pair of ASA’s. Employee’s traffic is handled by another pair of ASA’s.
Employee traffic flows from the 2960’s, past an L3 SVI on the 6509, then through the Employee ASA’s, then to the ASR’s, then out to the ISP#1 or ISP#2
Web Server traffic flows from the 2960’s or 6509, to the Customer ASA, then to the ASR’s then out to ISP#1 or ISP#2. Web server traffic does not flow through an L3 SVI.
The goal is to allow employees the ability to have the most bandwidth they can, however customer traffic always has to be preferred in the event of a ISP circuit approaching its limit.
This past networkers I was at the Cisco booth discussing how the 2248 can connect to the 5548 and have server connectivity. It was told to me that now, as of a fairly recent NX-OS release, you can have the 2248 going dual-homed to both 5548 via VPC and then have a server connected to both 2248 and be in active-active mode. Is this correct?
When we first deployed our 5548 and 2248 we had to put the 2248 in a straight pin mode, where it only had connections to one 5548 and then the server would dual connect to the 2248's and be in active-active mode. I was told that this changed with an NX-OS release however documentation still seems to be fragmented on what exactly is the case.
I have been recently asked to design a network. What I have for equipment is four 2960G's and one 1941 router. One switch is a root switch and the other three will have end devices on them.I have decided on three V lans to go with: VLAN20 Data, VLAN30 ISCSI, and VLAN99 Management each with seperate trunk links and redundancy (see picture below).
I have a seperate trunks for each V lan using the switch port trunk allowed. With exception to the Data V lan.My design has the Data V lan as the native because it is going to be receiving untagged traffic from the external network. I have set up inter v lan routing on the 1941 via sub-interfaces to allow them to talk to each other (or because of allowed they cannot?). I have one port coming from my router to my switch via Ethernet cable which is my bridge out. I have my external port doing a NAT translation for my inside addresses and a Default route set up ip route 0.0.0.0 0.0.0.0 gig0/0. I am using rapid- PVST to prevent loops and provide my zero downtime convergence when a link goes down. As it stands right now I cannot talk out of my network or inside of my network.
You can see it is highly redundant and I do not want to change it. This network is going to be deployed but there will never be anybody physically there to manage it which is why I made it as redundant as humanly possible.
We have our network setup as displayed in the attached. We have 2 HQ offices and 1 branch office. The branch office needs to connect to resources located at both HQs but taking the most effecient path. We have ethernet circuits connecting from each HQ to 2 x Cisco 3560 switches in the branch. HSRP has been configured on the 3560 switches with SW1 as active and SW2 as standby. OSFP has been configured in a single area 0 and the path cost on the link between HQs has been increase to allow 3560 SW1 to route to HQ1 directly and HQ2 via 3560 SW2.The 3560s are connected with a trunk with a L3 SVI for OSPF. This seems to work ok but I have noticed that the branch could become transit if the HQ1 to HQ2 link breaks. How can this be avoided? I realise that if we configure the branch subnets and SW1 to SW2 link in a stub area (area1) then all traffic will route from SW1 to HQ1 and will never share over SW2. I'm assuming that this is because OSPF chooses inter-area routes over intra-area.
remote location on MPLS circuit terminated on a Cisco router that has Internet connectivity through Central Site router. We are installing a cable modem at the remote location that is to be used as the Primary Internet Connection but still be able to use Internet through MPLS if the cable Internet goes down. We want the failover/fallback to be handled automatically.
We have an ASA5505 for the cable Internet which then feeds into the ISPs modem.
At first I was thinking about getting a module for the remote router so the cable Internet could be terminated on the remote router as well but that introduces a single point of failure. I would also like to firewall both the MPLS and the cable Internet but if I do so on the ASA there is another single point of failure.
We are about to install a new network consisting of Cat 4500s with Sup7E at the Access Layer, with Nexus 7000 at the Distribution and Core layers. We have 14 floors with at least three 4500s on each floor. Within the office block where the Access Layer and Distribution Layer reside we need to support secure borderless networking using 802.1x to place users from different parts of the business into segregated networks at layer 3.All switches will have the feature sets to support MPLS/ VRF / OSPF / EIGRP / BGP etc.We quickly dismissed the idea of using VRF-Lite due to the sheer number of Vlans we would need to managage and maintain, the point to point links alone just to get one additional VRF on each floor required far too many Vlans.As a result we are now considering deploying MPLS. The obvious benefits include scalability and manageability, the fact that all switch to switch links can now be routed, instead of having to using SVIs.
some of our switches have the switchport mode trunk command configured between the 3750 switches but other 3750 switches connected to our 6509 core switch do not have the switchport mode trunk command to permit Vlans from going across the swtiches instead it has an ip address and says no switchport what is the difference between does two. Is trunking used only for Layer 2 and L3 is used to route interface vlans?
I would like to make a design with 4 Nexus 5596UP. 2 of them equipped with Layer 3 Expansion Module so they can serve as core layer and the other 2 Nexus used as Layer 2 for aggregation server layer.The 2 Nexus in the core layer will run HSRP and will peer with ISP via BGP for Internet connection The 2 Nexus in the aggregation layer will be configured as layer 2 device and have FEX and switches connected to them.What I am ensure of is how the vpc and port-channel configuration should look like between the 4 nexus. What I was thinking is to run vpc between the 2 Nexus in the aggregation layer and between the 2 Nexus in the core layer. Than I was thinking of connecting each Nexus in the aggragtion layer to both Nexus in the core layer using port-channel and vice-versa.
we are planning a Nexus datacenter project with this layout:Our experiences with Nexus switches are not so large until now and the manuals are very extensive.Both N5K´s should be connected directly with all 4 N2K switches. I did not find a layout like this in the manuals. Only a design,where only 2 N2K are connected to one N5K, with this fex config:Now I´m not sure if it is right to make a config like this with the same slots and fex´s or with different slots and fex´s.
I'm looking at adding a Cisco 3750-X switch running c3750e-universalk9-mz.122-55.SE1 (IP base license) into a stack of 3750-G switches running c3750-ipbasek9-mz.122-55.SE1.bin Given that the version and feature sets are the same I don't forsee any compatibility issues. Would there be any reason why a universal image wouldn't stack correctly with other switches running the single .bin file?
We have a stack of switches that is at the max number of members allowed in the stack. Problem is we are running out of port density and need to add more ports. So instead of adding a whole new stack I would rather replace 2 of the 24-port swicthes with 48-port switches.
If the two 24-port swicthes we are removing are stack members and neither of them are the stack master, I should be able to replace the 24-port switches with the 48-port switches without bringing the master offline? If the new 48-port switches are running the same IOS version as the current 24-port swicthes, they should add themselves to the stack?Would I have to tell the new 48-port swicthes what switch numbers they are replacing in order for them to be added to the stack since we are at the max number of members?Also since the 48-port swicthes are replacing 24-port switches will the master give the 48-port switches the configuration for only the 24-ports?
I have a network with a Catalyst 3750 as the main switch and then some Catalyst 2960 switches that are plugged in to that. I have a server running windows server 2008 with a couple of virtual machines running in Hyper-V. I created 4 VLANS listed below and gave the 3750 the following IP Address.I would like the 3750 to only be configurable from VLAN 40 but currently every VLAN can connect to it, I noticed in the standard web page settings there was a setting for "Management VLAN" but it was set to 1 and would not let me change it, I kinda assumed that was for the management port in the back.-Now the tricky part, I was trying to set up routing between the VLANs and so far I have only been able to get a sort of "all or nothing" routing to work. I can turn IP routing on and add two or more VLANs to the routing and it works fine. But what I was hoping to do is create a couple of "junction vlans" that would only route to one or two other vlans. For instance, I wanted to create a VLAN 100 that routed to VLAN 20 and 30 but nothing else. I also want to route VLAN 1 just to VLAN 30, and so on. I am able to do each one of the cases but only one, it seems like the switch only supports one "routing table" am I missing something or is this just a limitation of the switch?
Is a 3750 sw capable of handling full routing tables and what can you recommend in a small mutihomed BGP router or switch capable of handling full routing tables?
I have a network with several catalyst 2960 switches and one catalyst 3750. I have created two VLAN and set up the proper routing and everything is working fine there. I have a client/server application that used multicast in the initial start up for the client to determine available servers, the issue is one of my clients is on a different VLAN then the server. I am able to route the multicast using MVR as long as both the server and the client are plugged into the 3750 by creating a static route, making the server a source port and the client a receive port. Unfortunately I need the client and the server plugged in to different 2960s. My question is how do I establish multicast routing between the two and perferably do it dynamically (always route multicast traffic from one VLAN to another).
I have been looking into this for a while and I can't seem to figure out why my 2nd vlan is not able to connect properly to the net.
My switch has 12 ports where my devices connects directly, they are all on Vlan 1 and they all work perfectly. on Port 12 I have a dlink router that is connected to a cable modem. the dlink router has an Ip address of 192.168.0.20
I created a second vlan (vlan2) and enabled dhcp relay on it. then I assigned port 9 on the switch to (vlan2)my laptop which is connected to port 9 seems to get an ip address fine and able to ping only some devices on my network (vlan1) and is not able to go out to the internet. I think it has to do with the routes. [code]
I have the task of replicating the router config on a 3825 router on a 3750 switch. Reason is we are taking out the router and replacing it with the switch to make use of the router for other functions.
Below is main part of the router config:
! ip source-route ip cef ! ! multilink bundle-name authenticated ! license udi pid CISCO3825 sn FCZxxxxxxx ! vlan internal allocation policy ascending
[code].....
The 3750 switch I have runs C3750E-UNIVERSALK9-M, Version 12.2(55)SE3 on a LAN BASE license.
The first thing I have done is to order for a license upgrade to IP BASE which would give the support for OSPF routing.I do not see much of an issue with the Interface configs, however, I am not too sure about replicating the routing config on the switch.
My question is can I run the commands as shown for the OSPF routing on the switch? If not, can I get suggestions on how best to set this up on the switch?
In 3750 switch,I have configured intervlan routing.I have three vlans Vlan 10,vlan 20,Vlan 30 and I have assigned IP address for that Vlan.In vlan 10,I have connected one systen gigabitethernet 0/1 interface.From my system I am able to ping vlan 10 ip address but I can't able to ping other vlan ip address (vlan 20,vlan 30).Is it possible to up the protocol for all that time.
For intervlan routing, Is 'IP routing' command enabled by default on a 6500 series switches based on the IOS?and on 3750 switches, do we need to enable the "ip routing" command manually for intervlan routing?
