Nexus 7k F1/F2 SoC MAC Table Learning

In case of M1 cards, understand the MAC addresses learned are communicated to all other forwarding engines.
Can someone explain how this happens in case of F1/F2 cards. Understand the full MAC address table doesn't get downloaded to all SoCs considering the limited resourses per SoC.
So how does MAC learning (from other SoCs / from M1 cards) and L2 forwarding happen on F1/F2?
TIA
Shijo George

Thanks manaik, bank-mapping did the trick! In the default vdc configure: "hardware access-list resource feature bank-mapping" and then I was able to have netflow and dhcp relay on the same interface.
I found another thread on the subject as well: https://supportforums.cisco.com/discussion/12075471/nexus-7k-dhcp-relay-w-ingress-netflow-sampling
Again, thanks alot!

Similar Messages

Interpreting MAC Table Data

Hello,
I was parsing ARP and then MAC table i.e. taking an entry from ARP table and looking for that mac address in the MAC table but for the same mac address I see several mac entries in the table. Any idea which one will be selected :
sh mac address-table
Legend: * - primary entry
        age - seconds since last seen
        n/a - not available
        S - secure entry
        R - router's gateway mac address entry
        D - Duplicate mac address entry
Displaying entries from active supervisor:
             vlan        mac address              type      learn      age         ports
---------+----------+----------------------------+--------------+-----------+------------+------------+-------------------------------------
       *       50       d44c.12e5.1f80       dynamic     Yes          0        Po1
               502      d44c.12e5.1f80       dynamic    Yes         130      Po1
               510      d44c.12e5.1f80      dynamic     Yes         130      Po1
        *      23        d44c.12e5.1f80      dynamic     Yes          5        Po1
        *      22        d44c.12e5.1f80      dynamic     Yes           0       Po1
Though the ports is the same for all values but not sure why so many entries for same mac address. The Legend says * is primary entry but again there are 3 such * entries
Thanks,

The MAC address itself will be globally unique, you are seeing multiple entries because the downstream switch is connected via a Port Channel.
If you were to logon to the actual switch where the host with that MAC was connected, you will find there is only one entry in the table for it.
Trace the MAC address to find out what device/host it belongs to and ensure on THAT switch, there is only one entry in the CAM table for it.
Po1 will be a trunk link to another switch yes? If the switch recieves a frame destined for that MAC address, it will forward it out of the Port Channel as that is the only outgoing port.
If you saw the same MAC appear in the table with multiple outgoing ports, then you would have an issue.

Switch mac address learning

Hi all, am i right in saying that if I had 2 switches plugged together, each switch wouldnt know about each others mac addresses until a host is passed through the uplink, can anyone tell me how the switch knows to use the uplink to find the yet un found mac address, does the switch forward the broadcast from the pc, then its learnt ?

You are right - they do not communicate their MAC tables to each other. The time a switch learns about a device connected to another switch is when a packet hits *that* switch.
Normally a broadcast will be carried across all switches in the VLAN, so when a PC arps, all switches will hear about it and add it to their tables. If after (by default) 5 mins, no traffic from said device hits the switch, it wll be removed from te table (cam aging).
So, with a simple network of two switches and everything in VLAN1, and three systems - A, B and C. A wants to talk to B. A&B are in switch 1, C in switch 2.
It sends a broadcast (ARP) which gets flooded to B, and via switch 2 and this seen by B. Switch 1 adds A to the address table, as does switch 2 - pointing at the inter switch link.
B unicasts the ARP response to A. Switch 1 adds B to the table and forwards the response to A as A is in the table. This does not get sent to switch 2. A&B talk to each other and the traffic is constrained to switch 1. After 5 mins the entry for A in switch two ages out and is removed.
A then starts to purely stream data to B. B does not bneed to respond. A stays in the table, but after 5 mins, B ages out. At that point, the traffic will be sent to switch 2, and seen by C as no switch knows where B is.
Because of whatever imaginary application is sending all this data, C sends a "quench" message to A. This gets flooded everywhere. the address of C is added to tables. A Acknowledges and responds, but carries on sending the traffic. As B is not in the table, the traffic is still flooded, but my totally imaginary application does somethin useful. It triggers a packet that gets a response from B. That puts B back in the filter table of switch1, and stops the traffic being flooded. If B sends anything o B, it will be flooded on switch 2, including to 1, but on 1 it will be sent only to B. any response to C will then put B in both tables.

RV325 System Log Entries - Kernel - kernel: The MAC table overflow. (Neighbour table overflow.)

Hello,
I have a RV325 Router. Entries in the System Log are repeated over and over.
The messages are:
2015-01-20, 04:11:59
Kernel
kernel: The MAC table overflow. (Neighbour table overflow.)
2015-01-20, 04:11:59
Kernel
last message repeated 8 times
2015-01-20, 05:52:19
Kernel
kernel: The MAC table overflow. (Neighbour table overflow.)
Packet traces point to thousands of ARP packets coming from the ISP to my WAN port. Most of the ARP packet sources/destinations are not even close to my ISP DHCP assigned IP.

Hi, Mark.
I'm not an Apache guru, but you may have two different issues here, depending on when the
kernel[0]: file: table is full
message is time-stamped relative to when you issue the
sudo apachectl start command.
1. Looking at the results of this Google search and some others tends to indicate that common causes for httpd could not be started are errors in the /etc/httpd/httpd.conf file.
You might also want to take a look at some of these other Discussions threads and in these "Networking and the Web" Discussion threads.
2. One explanation I've found for kernel[0]: file: table is full is here.
Hope these ideas help.
Good luck!
Dr. Smoke
Author: Troubleshooting Mac® OS X

SGE2010 MAC Table

I volunteer at a school who just purchased two 48 port SGE2010 managed switches. I am not a big fan of the web gui and was hoping to see the standard Cisco command prompt instead of the menu-type interface.
Is there a way to view the MAC table showing which MAC address is plugged into which port on the switch? I have been fighting with the menu and the gui for a while now and do not see this anywhere.
Thanks.

typolston,
When I ssh in (took me a while to realize I need to turn ssh on from console menu), I only see the text menu structure and no obvious option to go to a good old classic Cisco CLI. If you are implying that I can get to the cisco comand line just as if this were a catalyst, then I would like to know how to get there!
Just like this guy: https://supportforums.cisco.com/thread/2035492?tstart=-3
I'm not a huge fan of the feature-lacking-GUI
Thanks.

Arp table and mac table in cisco 4503 switch

Hi all,
I have a problem with 4503 switch
I have 7 highend servers in my lan i.e 5hp and 2dell servers.
Each server has 4 network interface cards(1g). so 7*4=28 ports.
I have create vlan 70, ip add is 10.70.70.1
I have assign ip address to servers like
first server         10.70.70.2, 10.70.70.12,
Second server   10.70.70.3, 10.70.70.13,
Third server        10.70.70.4, 10.70.70.14,
fourth Server       10.70.70.5, 10.70.70.15, 10.70.70.25, 10.70.70.35
fifth server           10.70.70.6, 10.70.70.16, 10.70.70.26, 10.70.70.36
sixth server          10.70.70.7, 10.70.70.17, 10.70.70.27, 10.70.70.37
seventh server      10.70.70.8, 10.70.70.18, 10.70.70.28, 10.70.70.38
The problem is in four interfaces each server, only one or two interfaces are pinging, remaining interface are not pinging.
for example in the first server i can able to ping 10.70.70.12- macid 60eb.69d2.a2aa
                                            i can't able to ping 10.70.70.2- macid 60eb.69d2.a2ab
second, fourth, fifth, sixth, and seventh continiously pinging successfully.
for example in fourth server i can able to ping 10.70.70.5 macid -b499.bafe.9c98
                                         i can able to ping 10.70.70.15 macid-b499.bafe.9c98
                                         i can able to ping 10.70.70.25 macid-b499.bafe.9c98
                                         i can able to ping 10.70.70.35 macid-b499.bafe.9c98
now you understand what is the problem, which server i am not getting pinging that arp table shows each interface separte mac address
                                                   which server i am getting pinging that arp table shows each interface bind with same mac address(dynamically)
Please give me the solution

Hi,
I Think you need to do Teaming on the servers.
++ configure etherchannel between switch and the server.
configuring etherchannel b/w 4503 and server:
================================
http://www.cisco.com/en/US/tech/tk389/tk213/technologies_configuration_example09186a008089a821.shtml
Sample NIC Teaming - HP NICs with Cisco Switches (EtherChannel) :
==============================================
http://support.citrix.com/article/CTX434260
There are several NIC teaming technologies available today from switch vendors. Cisco uses the term “EtherChannel.” Various switch vendors use various terms, and these may or may not provide the same exact functionality. Use of EtherChannel technology requires support from the server hardware vendor, NIC vendor, and Layer-2 switch vendor.
Hope this helps
Cheers
Somu
Rate helpful posts

MAC address learning

On various switches I have devices connected to, some of the ports never seem to learn the mac-address of the connected device. Anyone have an explanation or fix for why this randomly happens?

Hi Friend,
The switch will not learn a mac address till the time device connected to it send some request out from its source mac address.
Like a workstation if you connect to it and your pc is in hut state the switch will not learn a mac address.
Incase you power your pc up it will sned a broadcats ofr arp entry and that time switch will learn a mac address because now pc has send some request with its mac address.
So just check which all devices connected to the switch for which it does not learn mac address are those devices active and up in the network.
HTH, if yes please rate the post.
Ankur

CSS11800 mac table per switch or per VLAN

Hello
I have a scenario where the CSS11800 is seeing th same mac address from bultiple interfaces on an extreme switch as this is the way the extreme works.
Does the CSS11800 have a seperate mac database for each VLAN configured or does it have 1 per switch.
If it is per switch then I have a problem where the packets are being forwarded to the wrong interface sometimes.
Is there any way to resolve this on the Arrowpoint side as it cannot change on the extreme side.
Thanks
Micheal

Often times complex troubleshooting issues are best addressed in an interactive session with one of our trained technical assistance engineers. While other forum users may be able to help, its often difficult to do so for this type of issue.
To utilize the resources at our Technical Assistance Center, please visit http://www.cisco.com/tac and to open a case with one of our TAC engineers, visit http://www.cisco.com/tac/caseopen
If anyone else in the forum has some advice, please reply to this thread.
Thank you for posting.

MAC Address-Table Move Update Feature

Hi guys
Does 6500 SUP720/2T support MAC Address-Table Move Update Feature?
I cannot find it in anywhere..
Thanks very much!
QXZ

Hi,
Please refer following link :
http://www.cisco.com/en/US/products/hw/switches/ps708/products_tech_note09186a00807347ab.shtml
CAM
—All Catalyst switch models use a CAM table for Layer 2 switching. As frames arrive on switch ports, the source MAC addresses are learned and recorded in the CAM table. The port of arrival and the VLAN are both recorded in the table, along with a timestamp. If a MAC address learned on one switch port has moved to a different port, the MAC address and timestamp are recorded for the most recent arrival port. Then, the previous entry is deleted. If a MAC address is found already present in the table for the correct arrival port, only its timestamp is updated.
regards,
Ajay Kumar

Multicast mac address isn't learned, igmp-snooping

I have PIM router which connects to the cat 2960 switch and also I have host which connects to another port on the same switch. Host was joined to the IGMP group 224.1.1.1. I see that the router generates igmp-query and the host respons. IGMP-snooping process sees that process and updates appropriate entries:
2960-5#sh ip igmp snooping mrouter
Vlan ports
15 Gi2/0/32(dynamic)
2960-5#sh ip igmp snooping groups
15 224.1.1.1 igmp v2 Gi2/0/32, Gi2/0/33
But when I command "sh mac address-table multicast" I see nothing:
2960#sh mac address-table multicast
Vlan Mac Address Type Ports
What is reason of this problem?

There is the following statement from the "CCNP Practical Studies: Switching:
the process of populating the bridge table with multicast MAC addresses is based upon inspection of the destination MAC address, unlike unicast MAC addresses where the source MAC address of unicast frames is examined to generate bridge table entries.
And this book describes other parts of the mac learning process and says that after exchanging IGMP-message MAC-table must be populated by multicast mac-addresses. But later I found some Cisco and Jupiner documentation which says there is two way to perform multicast forwarding - MAC and IP. Default metod is IP multicast forwarding. When this metod is used multicast MAC-addresses isn't learnt and process of packet forwarding uses special forwarding cache which includes list of mapping IP and appropriate interfaces. It all means that this book isn't actual. All modern switchs perform multicast forwarding by IP metod and MAC-addresses don't populate CAM.

Can't clear mac address table from interface

hello all.
I'm facing a problem, and i've also tried to workaround but not sucessfully.
I've got a polycom phone on the swich. When I connect a laptop on that port, the mac address is learned by the switch and keep the mac address even if I disconnect the ethernet cable from that port and if I try to connect the same laptop on other port on the same switch I've got errdisable error in the last connected port. Although I was figuring out what's wrong and seems that the mac address is kept for some reason in the first port.
sw02#show mac address-table interface f0/19
Mac Address Table
Vlan Mac Address Type Ports
60 3c07.5417.9069 STATIC Fa0/19
80 0004.f21e.afa7 STATIC Fa0/19
this is a 2960, Version 12.2(44r)SE4
with a Polycom SoundPoint IP 330 connected on vlan 80
I was searching to clear the mac address table on that interface but the IOS version didn't give me the static option
sw02#clear mac address-table ?
dynamic dynamic entry type
move move keyword
notification Clear MAC notification Global Counters
As there's no dynamic entries on that interface the mac addresses remain on the f0/19 interface.
I've tried with other switches and with other laptops and is the same errdisable status.
sw02#show run int f0/19
interface FastEthernet0/19
description VoIP
switchport access vlan 60
switchport mode access
switchport nonegotiate
switchport voice vlan 80
switchport port-security maximum 5
switchport port-security
no snmp trap link-status
ip dhcp snooping limit rate 100
end
any thought?

the mac addresses are not manually configured.
yes, that's my point. when I disconnect the ethernet cable the mac addresses are not flushed from the mac table.
Although I don't understand why the mac addresses are kept in the interface, if I force the interface aging time to 1 min, the problem don't occur anymore.
I was reviewing the switch config and I've got ports with aging time 0 (that learn and flush the mac addresses dynamically) and I've got ports with aging time 1 (that learn and flush the mac addresses at the end of 60 seconds)
The problem is solved although I need to investigate this issue in other switch models and with other voip phones.
Tks Jon and Julio

Nexus 7k is going to be restarted if excute the claer mac address command

Hi all,
We are facing some issues in Nexus 7K.when we excute the clear mac address command,it is going to be restarted.
Could you please suggest me what might be the reason ?
Thanks & Best regards,
Krishna Chintada

I have no experience with Nexus but wondered if you could set the device to reload in 10 like in IOS and then clear the MAC address table. If it didn't restart after clearing the MAC table you could do reload cancel. Although the bigger issue still remains its probably a bug.

CSCui55504 - show Mac address table from RP gives an error msg and40;but from SP works )

Hello Cisco,
Is there any updates or ETA regarding this bug, as our production 6500 core switch is experiencing this issue and viewing mac-table is a critical activity we perform everyday to troubleshoot client connections.

I'm having this same issue. I also have this line in my log, which is curious:
12/14/14 7:13:07.822 PM netbiosd[16766]: Attempt to use XPC with a MachService that has HideUntilCheckIn set. This will result in unpredictable behavior: com.apple.smbd
Is this related to the problem? What does it mean?
My 2010 27" iMac running Yosemite won't wake up from sleep.

MAC Addressess not showing on my new 3560 switch

I have a Cisco 3560 (Switch B) switch I just introduced into my network. The gigabit ports are trunked from another switch (Switch A) to a Cisco 6509 WS (Main Switch).
crpf4bsw3#show cdp neighbors
Device ID            Local Intrfce         Holdtme   Capability    Platform   Port ID
crpf4bsw2.mdch.com
                    Gig 0/1               124            S I      WS-C3560-4Gig 0/4
crpcorsw1.mdch.com
                    Gig 0/4               127           R S I     WS-C6509-EGig 2/8
interface GigabitEthernet0/4
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,19,124,150,160,164,168,224
switchport mode trunk
mls qos trust dscp
spanning-tree link-type point-to-point
interface GigabitEthernet0/1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,19,124,150,160,164,168,224
switchport mode trunk
mls qos trust dscp
spanning-tree link-type point-to-point
The trunk ports are working just fine. I have configured all necessary remote management with no issues. However, my access ports are not working. I have set them up exactly the same as the adjacent switch A and it works just fine, but the same configuration on the new switch has not been able to pull IP information. I have provided information as to how the switch access ports are configured on both Switch A (working) and Switch B (not working).  I should note that I tried this with a Cisco 7940 phone and it got stuck on "configuring IP" then I tried it with my laptop and it pulled a 169 IP address. Both were direct connections into switch B. When I run a show mac-address-table, neither device shows up in the table. Only the gig port MACs. Any thoughts? Please let me know if you need any more information.
interface FastEthernet0/3
switchport access vlan 124
switchport mode access
switchport voice vlan 224
switchport port-security maximum 3
switchport port-security
switchport port-security aging time 2
switchport port-security violation restrict
switchport port-security aging type inactivity
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
mls qos trust device cisco-phone
mls qos trust cos
auto qos voip cisco-phone
spanning-tree portfast
spanning-tree bpduguard enable

Hi Mike,
It looks like you're guiding me in the right direction. I did a "show port security interface fa0/2" on the new switch and nothing was out of the ordinary with the exception of the 0 MAC addresses learned. But then I did a "show spanning tree vlan 224" Here's what I found:
Switch A (existing switch):
crpf4bsw2#show spanning-tree vlan 224
VLAN0224
Spanning tree enabled protocol rstp
Root ID    Priority    4096
             Address     0012.44cc.68e0
             Cost        8
             Port        1 (GigabitEthernet0/1)
             Hello Time   2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority    32992 (priority 32768 sys-id-ext 224)
             Address     0013.60aa.7400
             Hello Time   2 sec Max Age 20 sec Forward Delay 15 sec
             Aging Time 300
Interface        Role Sts Cost      Prio.Nbr Type
Gi0/1            Root FWD 4         128.1    P2p
Fa0/1            Desg FWD 19        128.3    Edge P2p
Fa0/2            Desg FWD 19        128.4    Edge P2p
Fa0/3            Desg FWD 19        128.5    Edge P2p
Fa0/4            Desg FWD 19        128.6    Edge P2p
Fa0/5            Desg FWD 19        128.7    Edge P2p
Fa0/6            Desg FWD 19        128.8    P2p Peer(STP)
Interface        Role Sts Cost      Prio.Nbr Type
Fa0/7            Desg FWD 19        128.9    Edge P2p
Fa0/8            Desg FWD 19        128.10   Edge P2p
Fa0/9            Desg FWD 19        128.11   Edge P2p
Fa0/10           Desg FWD 19        128.12   Edge P2p
Fa0/11           Desg FWD 19        128.13   Edge P2p
Fa0/12           Desg FWD 19        128.14   Edge P2p
Fa0/13           Desg FWD 19        128.15   Edge P2p
Fa0/15           Desg FWD 19        128.17   Edge P2p
Fa0/19           Desg FWD 19        128.21   Edge P2p
Fa0/20           Desg FWD 19        128.22   Edge P2p
Gi0/4            Desg FWD 4         128.28   P2p
Fa0/29           Desg FWD 19        128.33   Edge P2p
Fa0/30           Desg FWD 19        128.34   Edge P2p
Fa0/31           Desg FWD 19        128.35   Edge P2p
Fa0/32           Desg FWD 19        128.36   Edge P2p
Fa0/33           Desg FWD 19        128.37   Edge P2p
Fa0/34           Desg FWD 19        128.38   Edge P2p
Fa0/35           Desg FWD 19        128.39   Edge P2p
Fa0/37           Desg FWD 19        128.41   Edge P2p
Fa0/38           Desg FWD 19        128.42   Edge P2p
Fa0/39           Desg FWD 19        128.43   Edge P2p
Fa0/40           Desg FWD 19        128.44   Edge P2p
Fa0/41           Desg FWD 19        128.45   Edge P2p
Interface        Role Sts Cost      Prio.Nbr Type
Fa0/42           Desg FWD 19        128.46   Edge P2p
Fa0/43           Desg FWD 19        128.47   Edge P2p
Fa0/44           Desg FWD 19        128.48   Edge P2p
Fa0/45           Desg FWD 19        128.49   Edge P2p
Fa0/46           Desg FWD 19        128.50   Edge P2p
Switch B (new switch):
Spanning tree instance(s) for vlan 224 does not exist.
So with this new information, and with my trunk configurations above, what did you mean by a disconnect on the trunk?

Host not showing up in ARP table

Hi,
I am having an interesting/weird problem with one of my Catalyst 6509 switches.
The setup is as follows:
HostA - Switch1 - Switch2 - HostB
There is routing in place for HostA to reach HostB and vica versa.
I am testing this using ICMP. There is nothing blocking ICMP traffic on any of the devices.
Problem in question: I can only ping HostB from HostA (or Switch1) if HostB is found in the ARP table of Switch2. Pretty normal you might say since we need Switch2 to route/switch the packet to HostB and that will of course only happen if the ARP table is populated.
But what happens is the following:
I ping from HostA to HostB. It fails. I check Switch2 and I see that HostB is nowhere to be found in its ARP table.
Next I ping HostB from Switch2 (5 packets). First packet fails, last 4 I get a reply. I check and see that now HostB is to be found in the ARP table of Switch2.
Now I ping HostB from HostA and it works fine.
This behaviour is happening for all hosts in the subnet (VLAN) of HostB. I cannot reach them until I ping them from Switch2, after which they're in the ARP table and everything works.
Maybe it something different than the ARP table not being populated all together, but that is for now all I noticed. Does this problem ring a bell with anyone. And is there a fix?
It looks to me like Switch2 is malfunctioning, although I have no idea what is. Furthermore this apears to be working ok for a lot (read: all) of the other VLANS on Switch2.
Anyway. I'd love some help in troubleshooting this one.
kind regards,
Kevin

This goes back to the way switches (or bridges) work. They have to see a frame from an end device to know its MAC address and once they see it they add an entry in their CAM (or MAC) table. The entry basically tells the switch that a specific MAC is reachable via a particular port and this is meant to prevent subsequent flooding of unicast frames. In short an end device needs to send at least one frame for the switch to 'see' it. Another point to remember is that each entry in the CAM table has an age associated with it and if a switch does not see subsequent frames from that host it will age out the entry and start flooding all frames destined to this MAC address until it is learnt again (and learning is done only when the owner of the MAC starts to communicate again).
Kevin,
Can you please explain your topology in a bit more detail? I am looking for information like what is the default gateway of each VLAN, how are the VLANs spread across the two switches, any HSRP configurations and if yes who is the active for what VLAN, routing between switches, etc. This will help us troubleshoot the problem in a more effective manner.

Nexus 7k F1/F2 SoC MAC Table Learning

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