Cisco Switching/Routing :: 4500 CAT Layer3 To Access Layer And MPLS Design Considerations
Mar 29, 2012
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.
I am planning on implementing a metro ethernet circuit to replace a more expensive circuit to connect my office and data center. This circuit will be configured by the provider in a 'transparent' manner, which will allow us to pass vlans freely over the circuit without having to create a QinQ tunnel. This is a layer 2 only metro ethernet circuit.Planning on connecting the office end to a 3750 (switch A) and the data center end to a 2960 (switch B). The data center end will have a couple of other 2960s hanging off of it for server connectivity (switches C & D). I plan to use a 2811 (router A)for layer 3 connectivity in the data center. Switch B will plug into router A and switches C & D will plug into switch B using two port-channelled links. I can post a diagram if needed.I will use rpvst here and configure switch B as the root bridge.There are about 10 vlans that I use between the office and data center. Router A is also used to connect to other environments such as staging, production and also to the internet. I think this should be a straight-forward configuration since it is mostly layer 2. Should switch B be the root bridge?
is it possible to run a Catalyst 4500 as pure Layer 2 Switch, i.e. disabling "ip routing", but still managing the switch via Fa1, i.e. the defautl mgmtVrf vrf ?I tried the following:
! no ip routing ! interface FastEthernet1 ip vrf forwarding mgmtVrf ip address 192.168.1.1 255.255.255.0 ! ip route vrf mgmtVrf 0.0.0.0 0.0.0.0 192.168.1.254 ip default-gateway 192.168.1.254
I was not able to reach the Switch even from the same subnet. Only after enabling ip routing I could manage the Switch. I haven't found any command to set ip default-gateway for a vrf. Any workaround to keep routing disabled, but still manageable via VRF?
I configured the interfaces individually at L3 and could ping across each link Example:
4500 Switch 2: 6500 Switch 1 int t5/1 - int g3/17 1 Gig fiber link tore down config tried second set of interface int t6/1 - int g8/17 1 Gig fiber link Ping successful
It has ip helper configured that points to DHCP.From 4500 switch port - port x connects to 2960 port.Port x is configured as trunk between 4500 and 2960.
2960 config vlan 10 name data
All user ports are configured under vlan 10 and as access ports.Port x is trunk port connected frpm 2960 to 4500 switch allowing vlan 1 and 10 only.This switch has no default gateway configured.
We connected user PC on 2960 switchports and they were able to get the IP from DHCP server and were able to access the network? My question is how users on 2960 switch are able to access the network without ip default-gateway configured on 2960 switch?
I'm looking for Routing Design scenarios to complete our configuration needs for remote branches. We will have two 1921 routers in each location, one with a T1 from our MPLS carrier, the other with a DSL connection from an ISP. The T1 router will have an assigned AS and use BGP to router back to head quarters. The DSL router will have an IPSec tunnel back to an ASA 5510 at head quarters. I envisions a GRE tunnel from the DSL router back to head end routers connecting to MPLS at head quarters. Not sure yet how to manipuate the routing between head quarters and the branches such that the T1 router is the primary route to and from the branches and the DSL router is for failover/backup.
I need to confirm internet access from remote network through MPLS cloud to another site. Let me explain. We have a MPLS network with Wind stream as listed in the visio drawing; site 1 has internet access through the Time-Warner cloud for all users. Site2 has internet access through the Wind stream MPLS router. Site three has no internet access, and only has LAN access layer2 through Windstream routers to Site1 for networks 192.168.0.0/24, 10.1.1.x/24. My question is can we give everyone at Site 3 internet access through the MPLS network down into Site 1 using the Time-Warner ISP cloud.
I placed routes on the Site 3 3750 stack IP route 192.168.50.x 255.255.255.0 to the interface of the MPLS router at site3, then at site 1 we have IP route 192.168.50.x 255.255.255.0 to the MPLS interface, and able to ping all anything on the 192.168.50.0 network. I added the IP route 0.0.0.0 0.0.0.0 192.168.50.x the MPLS router interface, we do not have internet access at Site 3 using Site 1 network.
I confirmed at Site 1 from the Cisco 3750 switch we can ping 4.2.2.2 = Google. How to confirm this will work and what’s required to complete this connection to give everyone at site 3 internet access through Site 1 Time-Warner.
My management has tasked me to give them a high level overview of the different switching we can choose for our new building.
This is what I know so far.4 Closets, each closet has 450 ports,One MDF room that is will contain one UCS Chassis and a Nimble iSCSI SAN.
I am working on the spreadsheet and it looks like this (Not totally filled):
2960s3560x3750x45064510Approx cost (Each, 48PORT, POE+, 10G uplink, Dual PS, IP BASE) 6K7K8K45K75KMax Capacity192432432192384Backplane speed206464520520ProLeast ExpensiveStackable to 9Stackable to 9ProDual PSDual PSDual PSDual PSDual PSProLayer 3 opt Layer 3 optDual SupsDual SupsConExpensiveExpensiveConNo Dual PSConLayer 2 OnlyCannot stack more than 4 For the MDF I would like to use 2 Nexus 5548's with FEX's, and the layer 3 daughter board. For the IDF's I was thinking of two 4010's.
I'm trying to add an outbound policy on Layer3 interface on a 6500. The will be used to prioritize voice traffic. The environment contains 2 sites with 2 6500's each with VSS and a metro Ethernet link between them. I seem to be having problems prioritizing the voice across this link.
Lately I have been noticing mac flap messages on some of our access layer 3750G switches. Just a little background on how this is setup.
These 3750G switches are stacked and uplinked to a distribution layer 3750E stack (2 switches) via cross stacked etherchannel. (Usually 4 links) The access layer switches are stricly layer 2 where the distribution layer 3750E is routing the VLANs at the access layer to to the core 6500 switches.
I have just about ruled out physical loops on these stacks for the reason that the Macs are flapping. I am seeing this on two different stacks now each having 3 switches in the stack at the access layer. The cross stack etherchannel is spanned across the first two switches at the access layer and connected to both switches at the distribution layer. I have checked the etherchannel status and all ports appear to be part of the etherchannel and they appear fine.
The mac addressses that are flapping are just plain old desktop machines that plug directly into the access layer. I usually see this when the mac is learned on a port such as when a machine is plugged into the network or reboots.
I'm looking to implement a vlan filter to keep unnecessary stuff off my access-layer. Things like IPv6, IPX etc. I really only want IPv4, ARP and 802.1q on these 4500s. I know on 3750, 3560s etc, when I create the mac access-list, I can do it by ethertype, but on the 4500, I dont have that option.
I've got a bunch of 3750-X switches all running IP Base and acting as a routed access layer. They run OSPF in a totally stubby area with the distribution layer (Nexus 7K) as the ABR. We also have a physically separate management network into which the fa0 management interface of the 3750-X is connected. The management network itself runs OSPF and has multiple subnets and external access.
On the 3750-X, I'd ideally like to be able to run some sort of separate OSPF process for the management network or at the very least have a static default route for management traffic pointing out the fa0 interface, but clearly not have it interfere with the main default route for data traffic coming from the N7K ABR. Normally I'd just create a management VRF, sling the fa0 interface into it and run a separate OSPF process in that VRF. The problem is you can't create VRFs in IP Base! Surely there must be a way to do this? Cisco don't really expect customers to upgrade to IP Services just to have a working OOB Management network, do they?!
My colleague and I have been having a discussion about using rapid spanning tree in the access layer. Most of our infrastructure has been migrated to a routed access layer with 3750s.
The idea was brought up to configure the switches with rapid PVST. On the surface, it seems like a better idea, faster convergence, in the event that spanning tree ends up being used for some reason. My colleague prefers sticking with standard PVST. His argument is that, in the event of a layer 2 loop, some consumer-level switches filter out BPDUs and if the control plane is overwhelmed, the shorter timers of rapid PVST just puts that much more of a burden on the CPU trying to regain control, whereas with standard PVST it will have around 20 seconds before it starts to engage. (It may still be overwhelmed, but the longer timer delays the additional burden.) He says he's seen this problem with rapid PVST and that his opinion is backed up by our Cisco rep. (I haven't spoken to him yet.)
In our model, it should be very rare -- pretty much never -- that we would layer 2 span another switch off of our access stack.
One suggestion I saw is to use BPDU Guard, which is a good suggestion as well.
But we have had experiences with overloading the control plane on a 3750. I believe that concern is valid. If the CPU can't service spanning tree. But I'm interested in hearing about other experiences people have had in terms of rapid spanning tree in the access layer, end users plugging in unauthorized devices and creating loops, and the effects when using rapid spanning tree vs standard spanning tree.
I recently was asked to turn a routed link between our HQ and our DR Site into a trunked link to allow us to span our main Server VLAN up to the DR Site.I was informed by the ISP that owns the 100Mb Leased Line between the sites that the link was configured to pass dot1q traffic and I should just have to configure my links at either end as trunks to get the link to come up.
There is a Cisco 3560 at either end with Layer 3 routing enabled (obviously as this was a routed link previously).So, I scheduled an outage and configured either end as a trunk links as follows and repointed any routes from the /30 routed addresses to the management addresses of the switches on either side:
***For info VLAN 15 is the DR Site and VLAN 11 is the Server range at our HQ and was available on the connected switch***
On a 4500 switch port , defined as access vlan 10, if the user connects his own dhcp server ( instead of the normal pc that should be connected ), will it cause issues with my existing network. the existing network is all static ip. In above case, will the dhcp server start looking out and assign dhcp ip's , if a user unknowingly removes his static ip and changes to obtain ip via dhcp option on the lan properties.
i am trying to configure my HP 420 access point. I have configure different SSID on it, This access point is connected to cisco 4500 switch, i have configure trunk on up link to access point.my problem is the client are not able to get an IP address form the correct vlan if i tagged the SSID to it.
in the following the output of show run int in cisco 4500 switch:
interface GigabitEthernet3/13 description ==== HP ACCess point ==== switchport trunk allowed vlan 99,130,132 switchport mode trunk
On a 4500 switch port , defined as access vlan 10, if the user connects his own dhcp server ( instead of the normal pc that should be connected ), will it cause issues with my existing network. the existing network is all static ip. In above case, will the dhcp server start looking out and assign dhcp ip's , if a user unknowingly removes his static ip and changes to obtain ip via dhcp option on the lan properties.
I configure 3750 stack switch as core and 2960 stack switches as access layer switches.I connected my laptop to one of my core stack in VLAN 10 and I am pinging to one of my server in VLAN 1. What will be the minimum latency at the time of inter VALN routing
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?
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.
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.
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.
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?
I have 4 Subnets VLAN 1 172.20.0.0/16 with the default GW 172.20.200.254 VLAN 10 192.168.10.0/24 with the default GW 192.168.10.2 VLAN 59 192.168.59.0/24 with the default GW 192.168.59.254 VLAN 130 192.168.130.0/24 with the default GW 192.168.130.254 [Code]....
With absolutly the same settings I did this with an HP E4200-12G L3 Switch (which is now doing the job) so there is no routing mistake in the other components.For me it looks like, the SG300 doesn't like to be NOT the default gateway.
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.
