How to Use GigaSMART Trailers

Required License: Base

Supported Devices : GigaVUE-HC1 Gen 2, GigaVUE‑HC1 Gen 3, GigaVUE-HC3 Gen 2, GigavUE-HC3 Gen 3, GigaVUE‑HC1-Plus, and GigaVUE-HCT

GigaSMART operations can add the GigaSMART Trailer to packets, providing metadata on where the packet was processed.

GigaSMART Trailers can be combined with other GigaSMART operations. Refer to How to Combine GigaSMART Operations for the valid combinations.

If a trailer is included, it can optionally include the original packet’s CRC as one field and a Source ID (Source port label) as another. The Source ID indicates where the packet entered the GigaVUE H Series node and how it was processed. The modified packet’s actual CRC is always recalculated to reflect its new length. Refer to the Source ID Field for information.

Trailer operations can be assigned to GigaSMART groups consisting of multiple engine ports. Refer to Groups of GigaSMART Engine Ports for details.

Refer to Supported GigaSMART OperationsSupported GigaSMART Operationsfor more details on the devices that support GigaSMART operations.

When you enable the Source ID field for the GigaSMART Trailer, the trailer includes an additional field that identifies the platform type, box ID, slot number, and port number of the network port where the packet entered the GigaVUE H Series node. Refer to Format of the GIGAMON_SRCID TLV for the exact details.

Keep in mind the following when configuring GigaSMART operations with a Source ID argument:

Feature

Description

Source ID Field in GigaSMART Trailer

The Source ID field in the Gigamon Trailer includes the following values:

o Platform Type – The type of GigaVUE node where the packet was first seen.
o Group ID – The cluster ID/group ID configured for the node on which the packet was received. The GigaVUE H Series uses cluster IDs.
o Box ID – The box ID is configured for the GigaVUE node on which the packet was received. Box IDs are used for the unique identification of nodes in a cluster.

Note:  The box ID field in the Gigamon Trailer supports box ID values from 1-63, inclusive.

o Slot ID – The slot ID for the port on which the packet was received.
o Port ID – The physical port number on which the packet was received.

This example creates a GigaSMART operation named src_headermask with Masking and Trailer components. This operation will mask packets using a static masking offset of 148 bytes that continues for the next 81 bytes, writing over the existing data with an FF pattern. Then it attaches a GigaSMART Trailer indicating the original size of the packet before masking, the original packet’s CRC, and the box ID, slot ID, and port ID of the physical input port on the GigaVUE H Series node. 1 shows the GigaSMART operation with masking and trailer components.

1 GigaSMART Operation with Masking and Trailer Components

You can also construct GigaSMART operations that remove the GigaSMART Trailer from packets. These operations are useful in cases where you have cascade connections – a tool port receiving packets with a GigaSMART trailer is physically cabled to a GigaVUE H Series network port, sending the packets received on the tool port back into a GigaVUE H Series node. You may want to remove the GigaSMART trailer before the packets are forwarded to other tools – that is when the special Remove Trailer argument comes in handy. 2 shows Remove Trailer enabled for a GigaSMART operation.

2 Remove Trailer Enabled

3 and 4 illustrate a situation where a GigaSMART operation that removes the GigaSMART trailer would be useful. Consider the physical deployment shown in 3:

■   The green illustrates a one-way cascade between a tool (output) port (port 1/1/x12) and a network (input) port (port 1/1/x9).
■   If traffic arriving on port 1/1/x12 includes a GigaSMART Trailer, you may want to use a Trailer Remove GigaSMART operation to remove it before logically forwarding traffic from port 1/1/x9 to another port on the GigaVUE.

3 Cascade Physically Cabled from Tool to Network Port

For example, consider the packet distribution shown in 4:

■   The map named add_trailer is bound to network port 1/1/x1..x2. It adds the GigaSMART trailer and sends it to tool ports 1/1/x5..x8.
■   Tool ports 1/1/x5..x7 are all connected to tools that expect the extra data in the GigaSMART Trailer.
■   Tool port 1/1/x8 is physically cabled to network port 1/1/x4 in a cascade. To remove the GigaSMART Trailer from packets arriving on this port before they are forwarded to tool port 1/1/x9, we have bound a map named no_trailer to network port 1/1/x4 that is configured to remove the GigaSMART Trailers from all arriving packets.
■   Tool port 1/1/x9 receives packets without the GigaSMART Trailer attached.

4 Removing the GigaSMART Trailer from a Cascade Connection

Cascade connections also make it possible for multiple GigaSMART trailers to be attached to the same packet. For example, consider the cascade shown in 4 and suppose that instead of the no_trailer map removing the GigaSMART Trailer on packets arriving over the cascade physically cabled from tool port 1/1/x8, there is a second GigaSMART operation adding another trailer. In cases like this, the GigaSMART adds the most recent trailer at the end of the packet.

The same principle works for the Remove Trailer operations:

■   The most recent trailer is removed from the end of the packet. Any other trailers are left intact by a single Remove operation.

The trailer inserted by the GigaSMART line card can be interpreted using a recent version of the Wireshark® Protocol Analyzer. Refer to the GigaSMART Trailer Reference for details on the GigaSMART Trailer and its TLVs.

This section provides reference information on the format, position, and contents of the Gigamon Ethertype and GigaSMART Trailer fields in a packet processed by the GigaSMART-HD0 line card.

Refer to How to Use GigaSMART Trailers for details on how the GigaSMART Trailer is used in packets.

This section describes the format of the GigaSMART Trailer. 5 summarizes the position and contents of the GigaSMART Trailer and the Gigamon Ethertype field ( 0x22E5).

5 GigaSMART Trailer Format

GigaSMART operations can insert metadata as a trailer at the end of the packet. As shown in the following figure, the GigaSMART Trailer consists of one or more TLVs, followed by the Trailer Length Field. The GigaSMART Trailer is followed by the Gigamon Ethertype, a Checksum, and a recalculated CRC for the packet.

(Type1, Length1, Value1)(Type2, Length2, Value2)(Type(n), Length(n), Value(n))(Length Indicated by Length Field)

Trailer Length(1 Byte)

Gigamon Ethertype (0x22E5) (2 Bytes)

Checksum(2 Bytes)

Table 6: Gigamon Trailer Format lists and describes each of the fields in the GigaSMART Trailer:

Table 6: Gigamon Trailer Format

Field

Description

TLVs

TLVs are used to carry the metadata inserted by GigaSMART operations. Within a TLV, the Type and Length fields are each one byte long. The length field indicates the size of the Value field.

Refer to GigaSMART Trailer TLVs for a summary of the available TLVs and their formats.

Length

Specifies the size of the GigaSMART trailer. The Trailer Length does not includes the length bytes

Gigamon Ethertype

Two-byte field identifying packet modified by GigaSMART line card. Value is 0x22E5. Protocol analysis equipment can use the Gigamon Ethertype in the trailer to find the start of the trailer:

● Move one byte to the left to find the Trailer Length Field.
● Read the number of bytes for the Trailer Length and move the number of bytes specified to the left to find the start of the Trailer.

Checksum

Two-byte field used to validate that the extra data is, in fact, a trailer and not random data with the Gigamon Ethertype.

This section lists and describes the format of the Gigamon TLVs used in this release. TLVs are used to carry the metadata inserted by GigaSMART operations. Within a TLV, the Type and Length fields are each one byte long. The size of the Value field is indicated by the Length field.

Table 7: Gigamon TLVs

Tag Type

TLV ID

Value Field Length (Bytes)

Description

GIGAMON_PKT_LEN

1

2

Original Packet Length

This TLV is included in any packet with a GigaSMART Trailer – adding the Trailer changes the original packet length.

GIGAMON_SRCID_G

2

3

Original Packet Source Identifier

This TLV is included in any packet processed by a GigaSMART operation configured to include the Source ID (Source port label) field as part of its trailer. Refer to Format of the GIGAMON_SRCID TLV for a description of how the physical input source is encoded.

GIGAMON_CRC

7

4

Original Packet CRC

This TLV is included in any packet processed by a GSOP configured to include the original packet’s CRC as part of its trailer (If the CRC option is selected in the Trailer Add argument).

GIGAMON_SRCID

8

4

Original Packet Source Identifier ( GigaVUE H Series)

This TLV is included in any packet processed by a GigaSMART line card on a GigaVUE H Series node configured to include the Source ID (Source port label) field as part of its trailer (If the SRCID option is selected in the Trailer Add argument). Refer to Format of the GIGAMON_SRCID TLV for a description of how the physical input source is encoded.

The GIGAMON_SRCID TLV is included in any packet processed by a Source ID(Source port label) GigaSMART operation. The GIGAMON_SRCID TLV consists of 3 bytes indicating the platform type, group ID, box ID, and port ID for the physical port where the packet entered the GigaVUE H Series node:

GIGAMON_SRCID TLV (32 Bits/4 Bytes)

Platform(6 Bits)

Group ID(4 Bits)

Box ID(6 Bits)

Slot ID(6 Bits)

Port ID(10 Bits)

 

Name

Description

Bits

Platform

The type of GigaVUE node where the packet was first seen. Can be one of the following:

o Unknown
o GigaVUE-HCT
o GigaVUE‑HC1
o GigaVUE‑HC1-Plus
o GigaVUE‑HC3
o GigaVUE‑TA25
o GigaVUE‑TA25E
o GigaVUE-TA100
o GigaVUE-TA200
o GigaVUE‑TA200E
o GigaVUE‑TA400
o GigaVUE-TA400E

For bitmapping details, refer to the Platform Mapping

6

Group ID

The “Group Id” ranges between 0 and 15. For standalone devices, it is set to 0 and for the devices in a cluster, it reports the corresponding cluster ID.

4

Box ID

Box IDs are used to uniquely identify nodes in a cluster. Standalone systems typically have a default box ID of 1 here.

Note:  The box ID field in the Gigamon Trailer supports box ID values from 0-63, inclusive. Box IDs within the range 1 to 63 will be displayed in the SRC TLV. For any other value, the Box ID will be shown as zero.

6

Slot ID

The number of the slot including the physical port for the packet.

6

Port ID

The physical input port number for the packet. Refer to Port ID Values by Line Card Type for a summary of the values used by GigaVUE H Series line card.

10

The following table summarizes the bitmapping details for the platforms:

Platform

Ports SCRID Value for Platform Type

GMON_GS_CHASSIS_TYPE_HCT

26

GMON_GS_CHASSIS_TYPE_HC1

15

GMON_GS_CHASSIS_TYPE_HC1P

16

GMON_GS_CHASSIS_TYPE_HC3

17

GMON_GS_CHASSIS_TYPE_TA25

21

GMON_GS_CHASSIS_TYPE_TA25E

25

GMON_GS_CHASSIS_TYPE_TA100

13

GMON_GS_CHASSIS_TYPE_TA200

19

GMON_GS_CHASSIS_TYPE_TA200E

24

GMON_GS_CHASSIS_TYPE_TA400

23

The following table summarizes the values inserted in the GIGAMON_SRCID TLV for the port ID by GigaVUE device and the line card type:

GigaVUE Device / Line Card

Ports

Port IDs Inserted in Gigamon Trailer

GigaVUE‑HC1 Gen 2

HC1-X12G4

x1..x12

5..16

g1..g4

1..4

BPS-HC1-D25A24

x1..x4

53..56

x5..x8

49..52

PRT-HC1-X12

x1..x12

49..60

GigaVUE‑HC3 Gen 2

PRT-HC3-X24

x1..x24

1..24

PRT-HC3-C08Q16

c1..c8

1, 5, 9, 13, 17, 21, 25, 29

PRT-HC3-C08Q16–4x10Gb Mode

c1x1–x4.. c8x1–x4

1..32

PRT-HC3-C08Q16–4x25Gb Mode on Control Card Version 2

c1x1–x4.. c8x1–x4

1..32

SMT-HC3-C05

c1..c5

1, 5, 9, 13, 17

SMT-HC3-C05–4x10Gb Mode

c1x1–x4.. c5x1–x4

1..20

SMT-HC3-C05–4x25Gb Mode on Control Card Version 2

c1x1–x4.. c5x1–x4

1..20

BPS-HC3-C25F2G

 

x1..x16

1..16

c1..c4

17, 21, 25, 29

BPS-HC3-C35F2G

 

x1..x16

1..16

c1..c4

17, 21, 25, 29

BPS-HC3-Q35F2G

 

x1..x16

1..16

q1..q4

17, 21, 25, 29

PRT-HC3-C16

c1..c16

1, 5, 6, 10, 11, 15, 16, 20, 21, 25, 26, 30, 31, 35, 36, 40

PRT-HC3-C16–4x10Gb Mode

 

 

 

 

 

 

 

c1x1..x4

1..4

c3x1..x4

6..9

c5x1..x4

11..14

c7x1..x4

16..19

c9x1..x4

21..24

c11x1..x4

26..29

c13x1..x4

31..34

c15x1..x4

36..39

PRT-HC3-C16–4x25Gb Mode

 

 

 

 

 

 

 

c1x1..x4

1..4

c3x1..x4

6..9

c5x1..x4

11..14

c7x1..x4

16..19

c9x1..x4

21..24

c11x1..x4

26..29

c13x1..x4

31..34

c15x1..x4

36..39

GigaVUE‑HC1 Gen 3

HC1-X12G4

g1..g4

1..4

x1..x12

5..16

PRT-HC1-X12

x1..x12

1..12

PRT-HC1-Q04X08

c1..c4

25, 29, 37, 33

x1..x8

41..48

GigaVUE‑HC3 Gen 3

PRT-HC3-X24

x1..x24

1..24

PRT-HC3-C08Q08

c1..c8

1, 5, 9, 13, 17, 21, 25, 29

SMT-HC3-C05

c1..c5

1, 5, 9, 13, 17

SMT-HC3-C08

c1..c8

1, 5, 9, 13, 17, 21, 25, 26

PRT-HC3-C16

c1..c16

1, 5, 6, 10, 11, 15, 16, 20, 21, 25, 26, 30, 31, 35, 36, 40

GigaVUE‑HC1-Plus

HC1P-C04X08

 

c1..c4

1, 5, 9, 13

x1..x8

17..24

PRT-HC1-X12

x1..x12

1..12

PRT-HC1-Q04X08

c1..c4

25, 29, 33, 37
 

x1..x8

41..48

GigaVUE-HCT

HCT-C02

c1..c2

1, 5

PRT-HC1-Q04X08

q1..q4

1, 5

x1..x8

 

PRT-HC1-G12

g1..g12

1..12

GigaVUE TA Series

GigaVUE‑TA25

x1..x48

c1..c8

c1x1..c1x4

c5x1..c5x4

1..48

49,53,57,61,65,69,73,77

49..52

65..68

GigaVUE-TA25E

 

x1..x48

1..48

c1..c4

49, 53, 57, 61, 65, 69, 73, 77

GigaVUE-TA100

 

c1..c32

1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125

c1x1..c32x4

1..128

GigaVUE-TA200

 

c1..c32

1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125

c33..c64

129..160

GigaVUE-TA200E

 

c1..c32

1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125

c33..c64

1..128

GigaVUE‑TA400

 

d1..d32

129..160

GigaVUE-TA400E

 

d1..d32

1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125

x1..x12

129,130

The following figures show a sample GigaSMART trailer with the packet length and source ID (Source port label) TLV included. The total length of the trailer in this example is 10 bytes, plus another 5 bytes for the Trailer Length, Ethertype, and Checksum fields.

GIGAMON_PKT_LEN TLV

GIGAMON_SRCID TLV

Trailer Length, Ethertype, Checksum

GIGAMON_PKT_LEN=1(1 Byte)

TAG_LEN=2(1 Byte)

PKT_LEN(2 Bytes)

GIGAMON_ SRCID Type(1 Byte)

GIGAMON_ SRCID Length(1 Byte)

Platform(6 Bits)

Group ID(4 Bits)

Box ID(6 Bits)

Slot ID(6 Bits)

Port ID(10 Bits)

Length=10 (0a) (1 Byte)

Ethertype=0x22E5(2 Bytes)

Checksum(2 Bytes)

 

8 Wireshark Decode of GigaSMART Trailer
■   Group ID will be set to zero even for the devices in a cluster.
■   The Trailer Addition/Removal GSOP does not support E-Tag clusters. GigaVUE-TA400, GigaVUE-TA400E and GigaVUE-HCT platforms support only E-Tag clustering. However, you can configure the GSOP on GigaVUE-HCT platform when operating in standalone mode.
■   In Gen2 cards, combinations of Trailer Addition with Tunnel Decapsulation are currently unsupported.