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7 votes
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Why did Netflix choose to use CIDR blocks of 100.64.0.0/10 as its private network IP space?

they seemed to choose to use 100.64.0.0/10 as their private network space, rather than 10.0.0.0/8 (or a subspace from it). What's the purpose? I don't see any obvious benefit, but I may miss some key ...
YLearn's user avatar
  • 27.4k
7 votes
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spanning tree RootGuard question on vPC switches

Based on the comments I think you are confused about guard root. You configure guard root on the downstream interfaces of all the switches, except the root switch. Basically, you are trying to protect ...
Ron Maupin's user avatar
  • 99.8k
5 votes
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Bridge Assurance with vPC on port type network

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. ...
Rooster's user avatar
  • 66
5 votes
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Gateway on Nexus 3500 with VPC

For your first question, enable 'peer-gateway' under the VPC domain settings. This allows for directed ping forwarding over the VPC peer-link. With core Nexus VPC peers, it is also recommended to ...
cmschmidt15's user avatar
5 votes

Does vPC peer-gateway cause unicast flooding

I don't think that peer-gateway is needed on SW-3 at all, as it serves somewhat of a corner case (see below), only useful if the the given nexus has SVIs (interface vlan XXX) and acts as default ...
Marc 'netztier' Luethi's user avatar
4 votes

vPC traffic flow question

It depends on whether you have a vPC between the aggregation and core layers. If the connection between (A1, A2) and (C1, C2) is a vPC, then the switch always prefers "local forwarding". That is, any ...
mere3ortal's user avatar
  • 2,416
4 votes
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Cisco nexus vpc spanning-tree port type trunk question

SW3 is a switch. By first principle, portfast [trunk] or port type edge [trunk] should not be enabled on ports that connect to switches, lest you risk loops if that other switch connects to some other ...
Marc 'netztier' Luethi's user avatar
4 votes

vpc/mlag block half of uplink?

The whole point of MLAG / VPC is to have both link active, as in a standard link aggregation. Otherwise there would be little benefit over xSTP (spanning tree) (yes it converges faster but it's much ...
JFL's user avatar
  • 19.7k
4 votes
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Arista MLAG: should I have a separate L3 interface for keepalive like in Cisco's NX-OS?

Arista still does keepalives between peers. MLAG Documentation for the peer-link statement states that you don't have to use the same link. An MLAG is formed by connecting two switches through an ...
Jordan Head's user avatar
  • 7,099
3 votes
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Regarding Tier0 switch to downstream servers connectivity

I think it’s mostly a cost and scaling issue. When operating in the scale those big networks operate, you don’t care about a single server losing connectivity, you think in scale of data centers ...
Teun Vink's user avatar
  • 17.4k
3 votes

Cisco ASA vPC configuration issue

This should work as long as you configure them properly. Below captures are from Best Practices for vPC on Cisco Nexus 7000 Series Switches
Hung Tran's user avatar
  • 3,754
3 votes
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Understanding virtual port channel peer switch command

Under normal conditions only the root ID and bridge priority of the VPC primary will be sent via VPC downstream links. Within VPC links only the operational primary transmits or processes BPDU's (nb -...
rnxrx's user avatar
  • 6,114
3 votes

Is it possible to make a truly active\active L3 VRRP\HSRP configuration between two Nexus in a vPC

You actually don't have to do anything. VPC paired Nexus work exactly as you want them to. The prerequisite is that all systems involved (i.e. the servers) are attached to the Nexus over a VPC ...
Marc 'netztier' Luethi's user avatar
3 votes
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vPC between Cisco nexus 9236C and 9336C

Unfortunately, no, this can't be done. The models have to be the same even if they're models in the same family. Here's an answer from a Cisco forum entry on this topic and link to better explain ...
Jesse P.'s user avatar
  • 4,690
3 votes
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Is internal network traffic sent to private subnets via their NAT Server?

Is internal network traffic sent to private subnets via their NAT Server? Internal traffic should never be NATted. NAT is a necessary translation between incompatible addressing schemes like sending ...
Zac67's user avatar
  • 84.8k
2 votes
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Regarding traffic blackholing in case of vpc and hsrp

I'll answer Q2 first: Suppose a PC in VLAN 100 sends a packet to a PC in VLAN 200. Let's say the packet takes the VPC link to 7K2. Since the active SVI is on 7K1, the packet is forwarded across ...
Ron Trunk's user avatar
  • 67.6k
2 votes
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Etherchannel Basics

Q1: The primary device in the VPC pair is the only device in the VPC pair that can send, receive or respond to BPDUs. As such the secondary device will only forward them along to their destination. ...
Zack Scaringello's user avatar
2 votes

Stacking Cisco Catalyst 3850 via Fibre?

This answer probably won't very useful today, but it's possible to stack 2960X via fiber. You need C2960X-FIBER-STK.
kajetan's user avatar
  • 21
2 votes

Virtual port channel topology with firewall

I don't know what you mean "FW01 and FW02 as a single entity". In most scenarios, the FW cluster are composed by 2 independent firewall talking via 1 o 2 HA links where one keeps active and other are ...
KorXo's user avatar
  • 1,152
2 votes
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mLACP or vPC on L3 interfaces

(m)LACP and vPC are Layer 2 technologies, thus they don't apply to layer 3 interfaces At layer 3 you use for example VRRP (to provide gateway to hosts) or routing protocols (like OSPF) to achieve ...
JFL's user avatar
  • 19.7k
2 votes

Single homed, dual homed and double sided vpc

You kind of answered it yourself. The advantage for each is an increased level of redundancy. The advantage of vPC is that is provides link redundancy as well as chassis redundancy. A dual-homed ...
John K.'s user avatar
  • 969
2 votes

Fabricpath or vpc back to back

Both approaches will work and are actively documented and supported. FP starts to really have a significant advantage if you have more than the 4 switches in your design and, particularly, if you ...
rnxrx's user avatar
  • 6,114
2 votes

Fabricpath or vpc back to back

You don't need fabricpath to run a vPC+ from a FEX. Fabricpath is really only useful in large data centers where you have a multiple tier topology (Core, Aggregation, Access). In a smaller setup ...
John K.'s user avatar
  • 969
2 votes
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vpc loop avoidance scenario

The VPC peer link has a few special roles - it carries the CFSoE traffic (mentioned below) to allow the peers to sync (enabled automatically when feature vpc is turned on) and carries traffic for ...
rnxrx's user avatar
  • 6,114
2 votes

vpc loop avoidance scenario

I'm not quite sure CFS is the thing preventing loops. It is more about syncing and consistency checks. There's a simple rule though: do not send traffic out of member port if it was received over a ...
ar_'s user avatar
  • 1,133
2 votes

GNS3 - configure two DHCP servers within one VLAN

In your topology the host in VLAN 101 connected to switch LAN_2 are in a separate network that those connected to switch LAN_1. This is because you have a router between them. So you have 2 distinct ...
JFL's user avatar
  • 19.7k
2 votes
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vPC problems between nexus 5k’s and 4500

So I figured out the issue: I had a non-L3 daughter card installed with an L3 LAN BASE license. So, I had to uninstall the license file. Before you do, beware that the license file is tied to your ...
Joe's user avatar
  • 51
2 votes
Accepted

Cisco Nexus vPC LACP bonding with server issue

Solution OMG! Problem was downdelay=1000 option from Linux BONDING_OPTS, As soon as i removed that everything started working, I reboot server 10 time and every single time vpc was up. I don't know ...
Satish's user avatar
  • 4,379

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