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Questions tagged [cisco-nexus]

For questions about the Cisco network product line, called Nexus. For instance, Cisco Nexus 3000, 4000, 5000, 6000, 7000 and 9000.

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1answer
37 views

Cisco nexus 9396PX TX output discard on 40G interface without link congestion

We have cisco nexus 9396PX with N9K-M12PQ module (12x40G Interface), We have 8x10G L3 LACP bonded connectivity with our ISP and so far so good no issue at all. but recently we migrated that LACP LAg ...
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0answers
35 views

Cisco nexus 9396 rebooted with reason xbar_client

Today my one of cisco nexus 9396PX switch got rebooted and this is what i found, based on following logs what could be wrong? We don't have Cisco support for this switch, trying to see if i can get ...
4
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1answer
62 views

Finding the root cause of Spanning-Tree recalculations (on Cisco Nexus 9000s)

I have a nagging Rapid PVST problem on some Nexus 9000 switches. Rapid-PVST keeps recalculating 3 to 5 times an hour. We have in this topology (summarized): Edge Router ...
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0answers
35 views

Cisco nexus spanning-tree logging to syslog

I am trying to send my spanning-tree events to remote syslog but somehow it doesn't work, This is what i have in my config. N3K# sh run | grep logg logging level spanning-tree 7 logging server 172.29....
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1answer
78 views

Does vPC peer-gateway cause unicast flooding

This is my network topology where I have SW-1 is configured for HSRP for multiple VLANs, SW-2 & SW-3 connected to SW-1 using vPC. Last few month I am dealing with this unicast flooding where ...
1
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1answer
51 views

Configure Nexus N9K-C93180YC-EX

I am configuring a switch for the 1st time (Cisco Nexus N9000 Switch) to do some server performance testing in my lab. I have the serial console working and can log into the switch and run commands. ...
3
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1answer
149 views

Strange flooding during installing new switch in network

This is very strange issue i am noticing. In our datacenter we have every switch in rack has cisco vPC configured in short whole datacenter running vPC so there is no loop for spanning-tree anywhere ...
4
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2answers
69 views

Stop Memcrashed amplification DDoS attack

DDoS is essential part of my life so i am back with more question, Yes we started getting memcache based UDP amplification attacks, all source ports are 11211 coming from many random source IPs, we ...
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0answers
35 views

sflow configuration Cisco Nexus 9396PQ

We have Cisco a Nexus switch with M12PQ 12x40G GEM expansion card. Today when i enabled sflow on one of 40G interface i got following error: # sflow data-source interface e2/12 In order to enable ...
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0answers
40 views

TCAM utilization on Nexus 9396 switches

I have Cisco Nexus 9396 switch which is running L3 mode and i have configured bunch of IPv4 access-list in Ingress for firewalling to block certain traffic. I am reading about TCAM and wanted to ...
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1answer
42 views

SFP compatibility on QLogic FC HBA and Cisco FC SFPs

I do have a server featuring a dual port QLogic FC HBA supporting 2/4/8G interface speed. On the other end there is a Cisco Nexus 5020 with N5K-M1008 module supporting 1/2/4G interface speeds. This is ...
2
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1answer
77 views

Cisco QoS trust and cos-dscp dscp-cos Mapping behaviors

Regarding our current Cisco QoS implementation, to get a deeper understanding I would have some questions I read this: https://www.cisco.com/c/en/us/support/docs/wireless-mobility/voice-over-wireless-...
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2answers
106 views

Looking for a sanitized Cisco NXOS configuration

This may sound a bit unusual, but I'm looking for someone who can answer with a sanitized NXOS configuration with the following features used: vPC FEX EIGRP, OSPF or ISIS (IPv4) HSRP or VRRP This ...
1
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1answer
65 views

Nexus 7K Xbar replacement

Does anyone know if the Xbar module (N7K-C7009-FAB-2) can cause any impact? The replacement will take action during the maintenance window, but better safe than sorry. Thanks in advance for answers
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2answers
64 views

How to check interface statistics via CLI on Cisco Nexus 9508 Switch?

Suppose for some reasons I don't have access to Cisco APIC GUI and I need to check interface statistics of a physical interface of a spine/leaf switch? Which command should I use? Should I go to some ...
3
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1answer
42 views

Cisco NX-OS licensing

I'm somewhat new to networking and I have been looking to pick up an older Nexus switch to learn more about it and the converged features. I found a Nexus 3048 (for what I assume to be a reasonable ...
4
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2answers
257 views

Nexus 3172T MTU

I am attempting to set the L3 mtu on a Nexus port. The mtu option is only available if I set "no switchport" which then prevents me configuring VLAN related settings. Am I missing something obvious? ...
4
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1answer
115 views

Cisco switch ports configuration with QSFP+ to (4) SFP+ Hydra Cable Assembly

I am connecting two cisco switches with QSFP+ to (4) SFP+ Hydra Cable Assembly. On one side I have Nexus N3K series switch with QSFP+ port and on other side I have 6500 series switch with SFP+ ports. ...
2
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1answer
36 views

QSFP BiDi 40GB with two LC-LC

This Cisco module QSFP-40G-SR-BD is Bi-Directional (BiDi) 40Gbps QSFP, which means a single link used for RX & TX, each link 20Gbps, two LC links in total gives 40Gbps connection. If we will use ...
2
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1answer
276 views

Multiple HSRP group on same VLAN interface

I have Cisco Nexus 9k switch and following is my HSRP configured with vPC interface Vlan100 description *** Public_1 VLAN *** no shutdown mtu 9216 no autostate no ip redirects ip address ...
3
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1answer
334 views

Cisco nexus 3048 SFP validation failed

I have cisco Nexus 3048TP switch (48x1G + 4x10G) Hardware cisco Nexus 3048 Chassis ("48x1GE + 4x10G Supervisor") Intel(R) Celeron(R) CPU P4505 @ 1.87GHz with 3665240 kB of memory. ...
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2answers
3k views

Cisco Nexus vPC LACP bonding with server issue

I am configuring vPC end to end till my server to get more bandwidth, and following is my scenario I am seeing one strange thing which is i configured vPC on N3k switch and then i configured my ...
5
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1answer
764 views

How to announce network to specific neighbor peer in BGP

I have following scenario where i already have 10G (A - BLUE Link) connectivity from ISP on SW1 and SW2 for redendency and i have configured eBGP and iBGP, Everything is good at this point, Now my ...
5
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1answer
331 views

How to resolve a spanning tree issue on a server trunk port?

I am having a very strange spanning-tree issue with Cisco Nexus switches. My server is connected to the TOR switch with trunk configuration because we have multiple VLANs on the server. When I reboot ...
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1answer
54 views

Why does this command fail ? Cisco Nexus5548

I'm wondering why the following command is invalid ? I don't have access to the switch, only to a read-only web-interface. It's a Nexus5548, and it does have an interface named "port-channel1". The ...
1
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1answer
360 views

ftp user in cisco nexus 5010 switch

How to create a ftp user in cisco nexus 5010 switch to archive for autobackup. Below command is working for normal switches like cisco c3850 but not for Nexus switches. Please advise #FTP Local User ...
3
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2answers
322 views

Control plane terminology - Cisco Nexus

Is it true to speak about layer 2 control plane (LACP, STP, etc), and layer 3 control plane (OSPF, EIGRP, etc) ? or do we have only a general control plane ? We know Cisco Nexus vPC cluster has a ...
2
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2answers
1k views

Cisco ASA vPC configuration issue

I have this scenario and trying to configure vPC for Cisco ASA 5585 (Active-Standby) Nexus vPC config: interface port-channel1 switchport mode trunk switchport trunk allowed vlan 10 speed ...
1
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1answer
1k views

nexus ospf network statement missing

In old school IOS we used to do router ospf 1 network 0.0.0.0 255.255.255.255 area 0 But in Nexus switch i am not seeing any command or related doc, how do i announce my subnet in ospf in nx-os My ...
1
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1answer
500 views

Cabling two access ports on the same switch from different VLANs

Theoretically would I be able to connect two switch ports together with a simple straight/cross cable on the same switch. If the two ports are in different VLANs (eg. 2 and 22) and ports are in ...
3
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2answers
558 views

vPC traffic flow question

This is going to be new network in my datacenter and i have question related vPC, as you can see i have A1/A2 switch (L3/L2 routing) in aggregation layer and C1/C2 switches for Core (L3 routing). I am ...
2
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1answer
93 views

Routing the same prefix to different destinations on the same router

I have a Cisco Nexus 7000 and have configured static routes to reach my internal networks on the Nexus 7000. During a DDOS attack, the Nexus 7000 receives a more specific route via IBGP to re-route ...
1
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2answers
231 views

Nexus 9396px FAN speed issue

When i load nxos.7.0.3.I2.2d.bin Software then FAN running very quiet in following speed switch# sh environment fan detail Fan: ------------------------------------------------------------------------...
2
votes
1answer
81 views

Juniper JunOS routing issue in v15.1.49

I have a Cisco Nexus that has a few vlans on it - total network size is 172.26.64.0/20 split into /24 vlans - each using the third octet as the vlan ID. It's IP is 172.26.x.254 on each vlan as the ...
1
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1answer
135 views

Cannot Access remote VLAN from LAN

My WS-650E is connected to the Nexus 5000 as described in the image. The Nexus has a 10G P2P link to remote Site on 172.16.1.0/24 subnet. There is no router between the 2 sites and the IP on the ...
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0answers
317 views

Cisco Nexus 7k Mac move

I have been troubleshooting a mac move behaviour on my core network, which is made of 2 Nexus 7K with F3 series modules. They are inter-connected with a fabricpath mode port-channel. All the remote ...
1
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2answers
311 views

Nexus 3064 strange CPU utilization

My SNMP monitoring showing Nexus 3064 switch CPU utilization 20% But on switch cpu history showing 72 Hour maximum CPU%, is this normal? # show proc cpu history 1 1 11 1 1 11 111 11 ...
1
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1answer
233 views

Cisco VRF with two ISP

I am posting this question to get better understand of VRF on Nexus switch. This is the scenario i have 10G_A link from my ISP running BGP on it, now i need more capacity so order second 10G_B link ...
3
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1answer
63 views

ACL on Nexus 3064PQ performance

We are using this switch as L3 and planning to run some ACL to stop bad traffic. I never run ACL on switches so wondering is there any performance impact or how bad it will be? if anyone has any ...
3
votes
1answer
376 views

Cisco Nexus C9396PX licence question

We have Cisco Nexus C9396PX and i want to run HSRP on this to do failover, I just looked at licence and its showing following does that mean switch has activated Layer 3 license? switch# show lic u ...
1
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1answer
181 views

Network design question for datacenter

We have new customer and they said their traffic requirement is ~40GB so i am planning to order some hardware and have some question or doubt in mind. I am planning to put Nexus 5000 for Core layer ...
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1answer
2k views

Nexus VPC Peer Link - does it carry unicast traffic?

Read from the doc that the VPC peer link only carry multicast/broadcast traffic under normal circumstances -> The vPC peer link carries control traffic between two vPC switches and also multicast, ...
2
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2answers
1k views

Configuring ACL for DNS

Just want to double check my work here, but the domain port is supposed to be specified with the actual DNS server, correct? I want to only allow the VLAN 5.5.5.0/24 to communicate with this server ...
3
votes
1answer
544 views

VXLAN on top of EIGRP/I-BGP

for labbing purposes, I have two NX-9000 that's connected to each other via EIGRP. Trying to have one as Spine switch and the other as Leaf switch. No redundancy/HA needed at the moment Could you ...
1
vote
1answer
423 views

Provide L3 gateways in a multi-tenant VXLAN environment with ASR9K and N9K

I'm trying to make a PoC about VXLAN, and I have a design issue. I have one c3750 per client, each 3750 is connected to an N9K with a single fiber (per client). So each N9Ks are connected to multiple ...
3
votes
1answer
169 views

Tapping Nexus 5k FEX uplinks

Very similar to this question, we are considering tapping the FEX uplinks that we have running from Top Of Rack to our Nexus 5k core switches. Has anyone had success with tapping those uplinks? I ...
2
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1answer
178 views

Why does a layer 3 hop use vrrp secondary on nexus 6001

I have a nexus N5K-C5672UP as core layer 3 for our VLAN's. VLAN 601 on core 2 is secondary vrrp: core 02: core02# show vrrp Interface VR IpVersion Pri Time Pre State VR IP addr ---------------...
3
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2answers
753 views

What is Interface's Nominal Bitrate?

If you check show int tranceiver command on Nexus Switch 10Gbit Ethernet port, the output shows the nominal bitrate is 12000 MBits/sec instead of 10000 MBits/sec. As I know 12 bytes Interframe Gap + 8 ...
3
votes
1answer
2k views

DHCP not working on clients connected to Nexus 3048 but works on SVI

I've a strange problem with a pair of Nexus 3048 Switches in a vPC configuration. Since the core are still under implementation we've hit an strange issue: clients can't get IP addresses from the ...
1
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1answer
628 views

Cannot enable Flow Control on Cisco Nexus 3048

I've a pair of Nexus 3048 running NXOS version 7.0(3)I2(2d) and I can't enable flow control on ethernet interfaces. When issuing the command: flowcontrol receive on it returns with: ERROR: This ...