GigaSMART Header Stripping

The following figures illustrate how the header-stripping operations work – you can see the original MPLS packet with its label stack intact, followed by a stripped packet with a recalculated CRC and a new ethertype field.

The example shown in Figure 3 illustrates a simple GigaSMART operation named HeaderStrip configured to strip MPLS headers and add a VLAN tag of 200. The operation is assigned to the GigaSMART group with the alias of gsGrp1.

Figure 54

Strip Header GigaSMART Operation for Stripping MPLS Headers

The example shown in Figure 4illustrates a simple GigaSMART header stripping operation named gtp-strip configured to strip GTP tunnel information. The operation is performed by the GigaSMART group with the alias of GS1.

Figure 55

Strip Header GigaSMART Operation for Stripping GTP Tunnel Information

Use the configuration shown in the following figure to strip Layer 3 GRE IP encapsulated packets.

The following figure shows L3 GRE IP encapsulation before and after stripping.

Use the configuration shown in the following figure to strip Layer 2 GRE Ethernet encapsulated (Transparent Ethernet Bridging) packets.

The following figure shows L2GRE Ethernet encapsulation before and after stripping.

To display header stripping statistics, select GigaSMART > GigaSMART Operations (GSOP) > Statistics.

Refer to Header Stripping Statistics Definitions for descriptions of these statistics as well as to GigaSMART Operations Statistics Definitions.

Figure 5 shows an example GigaSMART Operation configured to strip packets containing the FM6000 timestamp:

Figure 56

Strip Packets with FM6000 Timestamp

Figure 3 is an example GigaSMART Operation configured to convert packets containing the FM6000 timestamp to UTC and append the UTC timestamp to the Gigamon trailer:

Figure 57

Strip Packets and Append UTC Timestamp to the Gigamon Trailer

Figure 7 Map with Strip Header GigaSMART Operation is an example map using the strip header GigaSMART operation in Figure 6.

Figure 58

Map with Strip Header GigaSMART Operation

Note:  (There is one-to-one mapping between the GigaSMART Operation (gsop) and the map.

If there are multiple devices, each device can be configured with a different timestamp format. To configure this, use a different gsop and a different map for each device. For example, for packets arriving from FM6000 device1, configure a gsop for FM6000 device1 and associate it with map1. For packets arriving from FM6000 device2, configure a gsop for FM6000 device2 and associate it with map2.

All the maps can send all the packets to the same tool port.

To access GigaSMART within GigaVUE‑FM, access a device that has been added to GigaVUE‑FM from the GigaVUE‑FM interface. GigaSMART appears in the navigation pane of the device view on supported devices. Refer to Access GigaSMART from GigaVUE‑FM for details.

GigaSMART operations use Generic header strippingto remove any arbitrary headers from a packet. The headers are stripped based on the offset and the length of the header.

To perform the generic header stripping operation:

1.

Click GigaSMART on the left navigation pane. The GigaSMART Operation (GSOP) page is displayed.

Figure 59

GigaSMART Header Stripping

2.

In the Alias field, enter a name.

3.

From the GigaSMART group drop-down list, select a GigaSMART group.

4.

From the GigaSMART Operations (GSOP) drop-down list, select Header Stripping. A Header Stripping drop-down list is displayed.

Figure 60

GigaSMART Generic Header Stripping

5.

From the Header Stripping drop-down list, select Generic.

Figure 61

Generic Header Stripping Template

6.

From the Template drop-down list, select one of the following options:

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Custom

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PPPoE

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Cisco LISP

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L2MPLS

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Avaya SPB

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VPLS

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GRE

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VXLAN

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TRILL

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Brocade VCS

A custom template lets you strip any arbitrary headers from a packet.

To strip any arbitrary header from a packet:

1.

From the Template drop-down list, select Custom.

 

Figure 62

Generic Header Stripping - Custom

2.

Select the following options to determine the headers to be stripped:

Component	Description
Anchor Header 1	Specifies the protocol from where GigaSMART should start stripping the header. The following values can be specified: None, Eth, VLAN, MPLS, IPv4, and IPv6 The value None starts the header stripping operation from the start of the packet. If None is selected for Anchor Header 1, the Anchor Header 2 must also be set to None. The offset must not be set to end.
Offset	Specifies exactly from which end of Anchor Header 1 the stripping operation should start. You can specify the offset in terms of the following: Start—the header stripping operation starts from the left end of the Anchor Header 1. End—the header stripping operation starts from the right end of the Anchor Header 1. Integer—the header stripping operation starts from the specified integer offset of the Anchor Header 1. The integer value varies depending on the Anchor Header 1 specified.
Header Count	Specifies how many headers from the offset GigaSMART should remove. This is applicable when the packet headers are of known type. The known headers are as follows: Ethernet, VLAN, MPLS, IPv4, and IPv6. It is important to note that, if start is specified for offset, the Anchor Header 1 is already counted for stripping. So, the value specified in the Header Count excludes the Anchor Header 1. If None is specified for Anchor Header 1, the Anchor Header 1 is not counted for stripping. So, the Header Count counts the Anchor Header 1 for stripping operation.
Custom Length	Specifies how many bytes of packet GigaSMART should remove. If the packet headers are unknown, the custom length of the unknown header can be specified to strip the packets. A combination of Header Count and Custom Length can also be used to strip the known and unknown headers. If Custom Length is specified, do not select Any for Anchor Header 2.
Anchor Header 2	Specifies the protocol that should become the next header after the stripping operation is complete. The following values can be specified: None, Eth, VLAN, MPLS, IPv4, IPv6, TCP, UDP, and Any The value Any indicates that the next possible header can be any one of the options displayed for Anchor Header 2. The value None indicates that it is not necessary to mention the Anchor Header 2.

Note:  Generic Header Stripping cannot strip unknown headers with variable length.

The PPPoE template lets you strip the PPPoE encapsulated packets from the packet structure. Figure 12 illustrates a red outline around the frame that needs to be striped.

Figure 63

PPPoE Encapsulated Packets

To strip the PPoE encapsulated packets:

1.

From the Template drop-down list, select PPPoE. Refer to Figure 13.

Figure 64

Generic Header Stripping - PPPoE

By default, the following values are selected:

Field	Value	Description
Anchor Header 1 Offset	Eth End	Starts the header stripping operation from the right end of the Ethernet header.
Header Count	1	Strips the header next to the Ethernet Header.
Anchor Header 2	Any	Updates a valid protocol as the Anchor Header 2 in the packet. In this case, any IPv4 or IPv6 protocol can become the Anchor Header 2.

2.

Click OK. The header stripping operation is displayed in the GigaSMART Operations (GSOP) page.

Cisco LISP is used to carry original IP packets to support multi-homing. In this example, the IPv4 outer header, UDP header, and LISP header are stripped from the Cisco LISP header format. The LISP header is considered as an unknown header.

Figure 14 illustrates a red outline around the frame that needs to be striped.

Figure 65

Cisco LISP Encapsulated Packets

To strip the Cisco LISP encapsulated packets:

1.

From the Template drop-down list, select Cisco LISP.

Figure 66

Generic Header Stripping - Cisco LISP

By default, the following values are selected:

Field	Value	Description
Anchor Header 1 Offset	Eth End	Starts the header stripping operation from the right end of the Ethernet header.
Header Count	2	Strips the next two headers— IPv4 Outer Header and UDP from the packet.
Custom Length	8	Strips 8 bytes of the unknown packet header. LISP is an unknown header.
Anchor Header 2	IPv4	Updates IPv4 protocol as the Anchor Header 2 in the packet.

2.

Click OK. The header stripping operation is displayed in the GigaSMART Operations (GSOP) page.

The L2 MPLS packet, also known as VPLS, encapsulates Ethernet packets in the MPLS label stack. In this example, the outer Ethernet header and MPLS [PW Label] are stripped from the L2 MPLS encapsulated packets.

Figure 16 illustrates a red outline around the frame that needs to be striped.

Figure 67

L2 MPLS Encapsulated Packets

To strip the outer MAC header from the L2 MPLS encapsulated packets:

1.

From the Template drop-down list, select L2MPLS.

Figure 68

Generic Header Stripping - L2 MPLS

By default, the following values are selected:

Field	Value	Description
Anchor Header 1 Offset	None Start	Starts the header stripping operation from the start of the Ethernet header.
Header Count	2	Strips the first and the second header from the packet. The outer Ethernet header and MPLS [PW label] packet header are both removed. As Anchor Header 1 is set to none, the Header Count counts the first header for stripping.
Anchor Header 2	None	Signifies that there is no need to specify the Anchor Header 2. In this case, the IPv4 protocol forms the first header of the packet after the stripping operation is complete.

2.

Click OK. The header stripping operation is displayed in the GigaSMART Operations (GSOP) page.

VXLAN encapsulates Ethernet packets in IP using VXLAN header. In this example, the outer Ethernet header, outer IP header, outer UDP header, and VXLAN Header are stripped from the VXLAN encapsulated packets.

Figure 18 illustrates a red outline around the frame that needs to be striped.

Figure 69

VXLAN Encapsulated Packets

To strip the outer Ethernet frame from the VXLAN encapsulated packets:

1.

From the Template drop-down list, select VXLAN.

Figure 70

Generic Header Stripping - VXLAN

By default, the following values are selected:

Field	Value	Description
Anchor Header 1 Offset	Eth Start	Starts the header stripping operation from the start of the Ethernet header.
Header Count	3	Strips the next three headers—outer IP header, outer UDP header, and VXLAN header.
Anchor Header 2	None	Signifies that there is no need to specify the Anchor Header 2. In this case, the IPv4 protocol forms the first header of the packet. Note:  When the Anchor Header 1 is set to None, the Anchor Header 2 must also be set to None.

2.

Click OK. The header stripping operation is displayed in the GigaSMART Operations (GSOP) page.

TRILL encapsulates Ethernet packets in Ethernet frame to provide L2 layer routing in data centers. In this example, consider TRILL as an unknown header. This TRILL frame is stripped with the inner Ethernet header from the encapsulated packets. The combined length of TRILL header (6 bytes) and inner Ethernet header (14 bytes) is 20 bytes.

Figure 20 illustrates a red outline around the frame that needs to be striped.

Figure 71

TRILL Encapsulated Packets

To strip TRILL from the encapsulated packets:

1.

From the Template drop-down list, select TRILL.

Figure 72

Generic Header Stripping - TRILL

By default, the following values are selected:

Field	Value	Description
Anchor Header 1 Offset	TRILL End	Starts the header stripping operation from the right end of the outer Ethernet header.
Custom Length	20	Strips 20 bytes of unknown header from the packets. In this case, the TRILL and the inner Ethernet headers are stripped.
Anchor Header 2	IPv4	Updates IPv4 protocol as the second header in the packet.

2.

Click OK. The header stripping operation is displayed in the GigaSMART Operations (GSOP) page.

Avaya SPB (802.1ah) fabric encapsulates Ethernet packets using MAC-In-MAC headers. In this example, the outer Ethernet header and ITAG are removed from the packet structure.

Figure 22 illustrates a red outline around the frame that needs to be striped..

Figure 73

Avaya SPB Encapsulated Packets

To strip the outer Ethernet headers from the Avaya SPB encapsulated packets:

1.

From the Template drop-down list, select Avaya SPB.

Figure 74

Generic Header Stripping - Avaya SPB

By default, the following values are selected:

Field	Value	Description
Anchor Header 1 Offset	None Start	Starts the header stripping operation from the left end of the outer Ethernet header.
Header Count	2	Strips the outer Ethernet and ITAG headers from the packet.
Anchor Header 2	None	Signifies that it is not necessary to specify the next header. The inner Ethernet header becomes the first header after the stripping operation is complete.

2.

Click OK. The header stripping operation is displayed in the GigaSMART Operations (GSOP) page.

You can also strip the ITAG, inner Ethernet header, and VLAN from the packet structure.

Figure 24 illustrates a red outline around the frame that needs to be striped.

Figure 75

Avaya SPB Encapsulated Packets

To strip the inner Ethernet headers from the encapsulated packets:

1.

Select the following values to strip the inner Ethernet headers from the encapsulated packets:

Field	Value	Description
Anchor Header 1 Offset	Eth End	Starts the header stripping operation from the right end of the outer Ethernet header.
Header Count	3	Strips the ITAG, inner Ethernet, and VLAN headers from the packet.
Anchor Header 2	Any	Indicates that any valid protocol available after the header stripping operation can become the next header in the packet.

2.

Click OK. The header stripping operation is displayed in the GigaSMART Operations (GSOP) page.