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In order to display the ELAM results, enter the show dbus and show rbus commands. If there is
a high volume of traffic that matches the same triggers, the DBUS and RBUS might trigger on
different frames. Therefore, it is important to check the internal sequence numbers on the DBUS
and RBUS data in order to ensure that they match:

module-4(f4-l2-elam)# show dbus | i seq

port-id : 0x0 sequence-number : 0x868

module-4(f4-l2-elam)# show rbus | i seq

de-bri-rslt-valid : 0x1 sequence-number : 0x868

Here is the excerpt from the ELAM data that is most relevant to this example (some output is
omitted):

module-4(f4-l2-elam)# show dbus

--------------------------------------------------------------------

                       LBD IPV4

--------------------------------------------------------------------

ttl                 : 0xff            l3-packet-length    : 0x54

destination-address: 10.0.3.101

source-address: 10.0.5.101

--------------------------------------------------------------------

packet-length       : 0x66            vlan                : 0x9c4

segid-lsb           : 0x0             source-index        : 0xe05

 destination-mac-address : 8c60.4f07.ac65

 source-mac-address : 8c60.4fb7.3dc2

port-id             : 0x0             sequence-number     : 0x868

module-4(f4-l2-elam)# show rbus

--------------------------------------------------------------------

                       L2 RBUS RSLT CAP DATA

--------------------------------------------------------------------

de-bri-rslt-valid   : 0x1             sequence-number     : 0x868

vlan                : 0x37            rbh                 : 0x65

cos                 : 0x0             destination-index   : 0x9ed

With the DBUS data, you can verify that the frame is received on VLAN 2500 with a source MAC
address of 8c60.4fb6.3dc2 and a destination MAC address of 8c60.4f07.ac65. You can also see
that this is an IPv4 frame that is sourced from 10.0.5.101, and is destined to 10.0.3.101.

Tip: There are several other useful fields that are not included in this output, such as Type of
Service (TOS) value, IP flags, IP length, and L2 frame length.

In order to verify on which port the frame is received, enter the SRC_INDEX command (the source
Local Target Logic (LTL)). Enter this command in order to map an LTL to a port or group of ports
for the N7K:

N7700# show system internal pixm info ltl 0xe05

Member info

------------------

Type LTL

---------------------------------

PHY_PORT       Eth4/1

FLOOD_W_FPOE 0xc031

The output shows that the SRC_INDEX of 0xe05 maps to port Eth4/1. This confirms that the
frame is received on port Eth4/1.

With the RBUS data, you can verify that the frame is routed to VLAN 55. Notice that the TTL starts
as 0xff in the DBUS data. Additionally, you can confirm the egress port from the DEST_INDEX

Содержание N7700

Страница 1: ...ocol ICMP request to a host on VLAN 55 10 0 3 101 port Eth3 5 ELAM is used in order to capture this single packet from 10 0 5 101 to 10 0 3 101 It is important to remember that ELAM allows you to capture a single frame In order to perform an ELAM on the N7K you must first connect to the appropriate module this requires the network admin privilege N7700 attach module 4 Attaching to module 4 module ...

Страница 2: ...Device name Dev role Abbr num_inst SLF L3 Driver DEV_LAYER_3_LOOKUP L3LKP 4 SLF L2FWD driver DEV_LAYER_2_LOOKUP L2LKP 4 FRONT PANEL PORT TO ASIC INSTANCE MAP FP port PHYS MAC_0 RWR_0 L2LKP L3LKP QUEUE SWICHF 1 0 0 0 0 0 0 1 2 0 0 0 0 0 0 1 3 0 0 0 0 0 0 1 In the output you can see that port Eth4 1 is on F4 L2LKP instance 0 On the N77 M312CQ 26L module there are 6 F4 ASICs with 2 ports in each port...

Страница 3: ...d the trigger you can start the capture module 4 f4 l2 elam start In order to check the status of the ELAM enter the status command module 4 f4 l2 elam status ELAM Slot 4 instance 0 L2 DBUS LBD Configuration trigger dbus ipv4 ingress if source ipv4 address 10 0 5 101 destination ipv4 address 10 0 3 101 L2 DBUS LBD Configured ELAM Slot 4 instance 0 L2 RBUS Configuration trigger rbus ingress result ...

Страница 4: ...e bri rslt valid 0x1 sequence number 0x868 vlan 0x37 rbh 0x65 cos 0x0 destination index 0x9ed With the DBUS data you can verify that the frame is received on VLAN 2500 with a source MAC address of 8c60 4fb6 3dc2 and a destination MAC address of 8c60 4f07 ac65 You can also see that this is an IPv4 frame that is sourced from 10 0 5 101 and is destined to 10 0 3 101 Tip There are several other useful...

Страница 5: ...rsion 3 Description LTL Map for Crossbow LTL_TYPE SIZE START END LIBLTLMAP_LTL_TYPE_PHY_PORT 3072 0x0 0xbff LIBLTLMAP_LTL_TYPE_SUP_ETH_INBAND 64 0xc00 0xc3f LIBLTLMAP_LTL_TYPE_UCAST_VPC_VDC_SI 32 0xc40 0xc5f LIBLTLMAP_LTL_TYPE_EXCEPTION_SPAN 32 0xc60 0xc7f LIBLTLMAP_LTL_TYPE_UCAST_GENERIC 48 0xc80 0xcaf SUB TYPE LTL LIBLTLMAP_LTL_TYPE_UCAST_GENERIC_NOT_USED 0xcaf LIBLTLMAP_LTL_TYPE_DROP_DI_WO_HW_B...

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