11

While it is certainly a good idea that a VPC has the same allowed VLAN list on all sides, it is not a requirement. Take a look at the output of "show vpc consistency-parameters global". switch# show vpc consistency-parameters global Legend: Type 1 : vPC will be suspended in case of mismatch Name Type Local Value ...


11

An LACP PDU is around 110 bytes, so running them every second isn't likely to even register on an Ethernet link of any speed. I would recommend running in "fast" mode at all times for rapid detection of faults.


8

The power of 2 requirement varies per vendor/hardware/software. Cisco had (has) a pretty bad stigma against them with a lot of the earlier catalyst switches capable of 10G. The problem comes with how the software hashes (or "balances") data over the multiple ports in the port-channel (this is agnostic of PAgP or LACP). This post does an excellent job of ...


8

At layer 2, all load balancing is, at best, done by an XOR or hash of the source and destination MAC, and if you're lucky, it may even read into layer 3 and hash that data too. At layer 3, however, where we're basically talking about multiple gateways (so, effectively, two physical links with a unique next-hop across each) you can max out the bandwidth ...


8

As the firewalls aren't part of a vPC they won't be part of the normal vPC loop prevention. The loop prevention only states that a packet cannot ingress on the peer link if it is destined to go out another vPC enabled port. Not too sure on the multicast front as we don't use it in our environment and I haven't really looked into its behaviour on the 7K's. ...


8

Does setting a custom MTU on the host side of a LACP bond require also customizing the MTU on the switch side? Your data-link MTUs: On servers the data-link should always match between servers within the same broadcast domain, or vlan. This isn't critical for TCP services because of TCP MSS negotiation, but UDP services need matched MTUs if they send ...


7

LACP gives you a significant advantage in that it verifies connectivity in both directions over each link. You can think of it as also combining the features of UDLD with link aggregation. For example, imagine you have the links configured in "mode on". Now lets say one of the links from the 3750 to the 2960 fails but in only one direction, say the ...


6

Configure your Force10 with portmode hybrid and no spanning-tree pvst err-disable cause invalid-pvst-bpdu on the interface which faces the Cisco 6500... Reference: Force10 - Cisco STP Interoperability paper. This is the complete configuration for your Port-channel (however, see the warning below) interface Port-channel 2 portmode hybrid switchport no ...


6

Packet tracer is a simulation for Network academy not a IOS emulator (like say GNS3) if there is a conflict between the doc and packet tracer, packet tracer looses. If you read further in the documentation a LOT of things have to match for an etherchannel bundle can form and link speed is one of them. A corner case MAY be etherchannel autonegotated ports ...


6

You will need real switches since there is no emulator for their ASICs. GNS3 can emulate only routers (and run their IOS images). You can try Cisco Packet Tracer for switches, but keep in mind that it is a simulator and it does not have full set of features you will find on real equipment.


6

Yes, if I am reading things correctly it appears your understanding is correct. Yes, there are implementations that will allow you to do link aggregation between a host and two switches. Switch stacking will allow a stack of individual switches to be managed as one device. Typically one of switches in the stack becomes the master for the stack allowing it ...


6

Your ethernet SFP/SFP+ for fiber are going to be 1 or 10 Gbps. There isn't a 2 Gbps ethernet fiber SFP (some vendors used to count this way because of full duplex, but it is still 1 Gbps in each direction). You may be able to use LACP, depending on the switch vendor/model. Combining multiple interfaces into a single channel is really just fooling STP to ...


6

Scenario A: Switch 1 has ports 1+2 trunked together via LACP. They are plugged into Switch 2 ports 1+2. Both links will be used, but a single flow will only use one link. There is a hashing algorithm that determines which flow uses which link. If one of the links goes down, then all the traffic will be switched to the other link. This happens very rapidly....


5

First, let's be realistic about your system performance; you have to ensure that your system can consistently spool the bandwidth you're asking about from disk to the NICs in question (see bottom of answer)... As long as you're willing to use FTP for your file transfers, you can use a client that supports segmenting the file via FTP REST command for ...


5

Geekman, If talking in Cisco terms, the main difference between vPC and basic stacking (StackWise, FlexStack) is excluding of splitbrain situation, when both members become a master and continue to forwarding. Juniper EX series currently do not support any technology like vPC, so MLAG can be completed only with Virtual Chassis which can be splitbrained. ...


5

802.1x was specifically designed for end-point devices to authenticate to network switches and was not designed for switch-to-switch connections. Because of this, it is highly unlikely that you will find any switches that can be a 802.1x client, so the answer to your Y question is no. To answer your X concern (see XY problem)- preventing a malicious entity ...


5

Spanning-tree port type network activates bridge assurance on the link. Since the 2960X doesn't support bridge assurance, you can't run this link as port type network. Just run it in normal mode. About the only place you want to run port type network is on the vPC peer-link where it is enabled by default. From the best practices design guide: Bridge ...


5

Not sure what you tested. You need to aware that any single flow will only use one of the port combinations each way. Port aggregation allows you to increase the throughput for multiple flows, not for a single flow. How flows are distributed to the potential egress ports depends on the device. Most use either source/destination MAC addresses, source/...


5

Static LAG trunks are just that: static. When multiple interfaces are connected they are regarded as a single logical port. LACP trunks are negotiated by protocol. That way you can ensure that they are terminated correctly (each LACP group can only be connected between two switches). Incorrectly terminated interfaces are not added to the LAG trunk. You ...


5

The choice between using a L2 or L3 link is really independent of LACP. Assuming your LACP hashing algorithm choice uses layer 3 information to choose the link (and your ISP does the same), there is little difference.


4

The switch has a built-in help function: ? xa-eng(config)# trunk 1-2 trk17 trunk Do not use any protocol to create or maintain the trunk. lacp Use IEEE 802.1ad Link Aggregation protocol. <cr>


4

The issue is that the link speed of the suspended interface is not the same as the rest of the interfaces in the bundle. Your working interfaces are operating at BW 1000000 Kbit Whereas, your suspended interfaces are working at BW 100000 Kbit The most common problem for interfaces that refuse to come up to auto-1000 are damaged cables. This ...


4

Link aggregation / port-channel / lacp will not allow you to have a single stream to use several interfaces. Four different streams can use different physical interfaces, and each one could use 1Gbs (reaching 4Gbs total) but none of them will be able to achieve more than 1Gbs. Those protocols works with an algorithm that will choose a specific interface ...


4

first of all you need to know that using port channel mean you will maximum obtain one physical link speed (1G) per flow where flow means same source port and same destination port, so if you generate 2 traffic flow you will obtain speed of two physical link and so on . Versification there are two verification methods 1. from cisco side "show port-...


4

This problem happens because Linux bonding in 802.3ad mode sets all slave interfaces to the same hardware mac address ("borrowed" from the first enslaved interface). Then LACP PDUs are transmitted using this same mac address and each of the switches thinks it has direct connection to the server. At the same time, bonding drops packets which are received on ...


4

The main issue is not related to LACP, but to how L2 (with SVI) and L3 ports handle spanning tree: If you configure the link as L2 and configure an SVI, you will be running spanning tree on the Etherchannel (if it is enabled). This could have implications such as a 30 second delay before the Etherchannel transitions to Forwarding when it is brought up. If ...


4

The setup is totally valid, provided all devices support LACP LAG. Two things though: The network design is not very good, neither for reliability nor from the performance/efficiency perspective. Basically, don't chain but build a tree. If possible, connect the top three switches to the bottom one directly (or even the firewall), shortening forwarding paths,...


4

LACP is a protocol where both side negotiate the trunk - if either side doesn't use LACP both (all) links will stay separate. STP may step in and prevent a bridge loop. A static trunk uses no protocol. Once the links are up they are regarded as being trunked, whether or not the other side is set up in the same way. It's a good idea to use LACP whenever ...


4

From a functional point of view, there's no difference between LACP trunks and static trunks. All links are aggregated (with the limitations Ron has already pointed out) and the aggregation group is redundant. An LACP trunk set up with eight ports works with anything between one to eight physical links - so does a static trunk. The difference is that an ...


Only top voted, non community-wiki answers of a minimum length are eligible