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| | SNAP header - Wikipedia, the free encyclopedia |
 | | In LLC/SNAP encapsulation the SNAP header is preceded by a LLC header that consists of the 3 bytes | | | The Sub-Network Attachment Point header (SNAP header) is an IEEE-defined layer 2 encapsulation header format for Ethernet and similar network packets. | | | This reduces the size of the available payload for protocols such as the Internet Protocol to 1492 bytes, compared to the use of the Ethernet II framing. |
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http://en.wikipedia.org/wiki/SNAP_header
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| | RFC 2427 (rfc2427) - Multiprotocol Interconnect over Frame Relay |
| | A SNAP header is of the form: +--------------------------------------------+ | | | When a SNAP header is present as described above, a one octet pad is used to align the protocol data on a two octet boundary as shown below. | | | One should note that the Common PDU Header and Trailer of the encapsulated frame should not be simply copied to the outgoing 802.6 subnetwork because the encapsulated BEtag value may conflict with the previous BEtag value transmitted by that bridge. |
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http://www.faqs.org/rfcs/rfc2427.html
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| | davic-ip1394-00.txt |
| | The size of the link-fragment header is 4 bytes; the LLC/SNAP header is 8 bytes. | | | The SNAP header is used to identify the EtherType Code as listed in Assigned Numbers [7]. | | | The value of the EtherType in the SNAP header shall be 0x0800 for IP or 0x0806 for ARP. |
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http://ietfreport.isoc.org/idref/draft-davic-ip1394
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| | Mandragor & Apinc - Free Documentation Base |
| | SNAP: The SNAP Header is 5-bytes long and consists of a 3-byte Organizationally Unique Identifier (OUI) field and a 2-byte Protocol Identifier (PID) as shown in Fig. | | | The Frame Header is 24-bytes long and has several fields that are associated with the identification and control of the payload. | | | A maximally minimum size IP Packet is defined as an IP Packet with an 8-byte payload (the smallest possible non-zero payload size for a fragment) and a 60-byte header (the largest possible header consisting of a 20-byte fixed part and a maximum size option field of 40-bytes) [17]. |
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http://docs.mandragor.org/files/RFCs/26xx/2625
(12296 words)
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| | Ethernet: Questions & Answers |
| | The value of the SAP field in the 802.2 header is equivalent to the 'protocol type' field in the Ethernet II header. | | | In a SNAP frame, both the SAP values will be 0xAA and the first 5 bytes of the data will give the protocol ID. Out of the 5 bytes of data, the last 2 bytes are same as the protocol type field of the Ethernet II frame. | | | After this the Ethernet was standardized by IEEE and the new format is known as 802.3 format. |
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http://www.geocities.com/SiliconValley/Vista/8672/network/ethernet.html
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| | Ethernet Frame Types |
| | The first 3 bytes of the SNAP header is the vendor code, generally the same as the first three bytes of the source address, although it is sometimes set to zero. | | | Following the 802.2 header are 43 to 1,497 bytes of data, generally consisting of upper layer headers such as TCP/IP or IPX and then the actual user data. | | | Following the 802.2 header are 38 to 1,492 bytes of data, generally consisting of upper layer headers such as TCP/IP or IPX and then the actual user data. |
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http://ct.wacc.cc/cisco/AddCCNALinks/ethernet_frame_types.htm
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| | TABTOS(1NEMO) manual page |
| | If both times specified, and the header= has an associated time, the header value will be overriden with the user specified values. | | | without a header) can also be processed if the user specifies how many bodies are present per snapshot. | | | A list of variables that are present in the header, in the order given. |
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http://bima.astro.umd.edu/nemo/man_html/tabtos.1.html
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| | Ethernet |
| | This is now supported in the IEEE 802 protocols using the SNAP header. | | | This length field was soon re-used in Xerox's Version 2 Ethernet as a label field, with the convention that values between 0 and 1500 indicated the use of the original Ethernet format, but higher values indicated what became known as an EtherType, and the use of the new frame format. | | | In principle this is not interoperable with the other later variants of 802.x Ethernet, but since IPX has always FF at the first byte (while LLC has not), this mostly coexists on the wire with other Ethernet implementations (with the notable exception of some early forms of DECnet which got confused by this). |
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http://www.sciencedaily.com/encyclopedia/ethernet
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| | Ethernet Standard Encapsulation |
| | IEEE 802 Ethernet defines an Ethernet-specific header (802.3), and a media-independent header (802.2). | | | This makes packets smaller, but since the 802.3 header does not contain a type field, this method can't be used with multiple protocols on the same Ethernet, or confusion would result. | | | Encapsulating IP with this scheme produces a packet starting with an 802.3 header, then an 802.2 header, then a SNAP header, then the IP packet. |
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http://www.freesoft.org/CIE/Topics/62.htm
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| | RFC 1954 (rfc1954) |
| | The transmitted value of the Checksum field is the checksum value that would have been computed for the entire IP header if the TTL field had been set to zero (i.e., the actual value of the TTL field is "subtracted", using one's-complement arithmetic, from the Checksum before transmission). | | | This is the null encapsulation of section 5.1 "VC based multiplexing of routed protocols" from RFC 1483 [RFC1483]. | | | The LLC/SNAP header is prefixed to the IP datagram and the entire packet is encapsulated within the payload of an AAL-5 CPCS-PDU as specified in RFC 1483 and illustrated below: Newman, et. |
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http://www.cse.ohio-state.edu/cgi-bin/rfc/rfc1954.html
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| | [No title] |
| | FC Header Code Points The fields of the Fibre Channel Header are depicted in figure 4. | | | LLC/SNAP Header The fields of the LLC/SNAP Header [IEEE-LLC] are depicted in figure 6. | | | The Data Field is of variable size, ranging from 0 to 2112 octets, and includes the user data in the Frame Payload field, and Optional Headers. |
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http://mirror.aarnet.edu.au/pub/rfc/rfc3831.txt
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| | [No title] |
| | With a MAC header+trailer of 36 octets and the LLC+SNAP header of 8 octets, the IP datagram (including IP header) may not exceed 8188 octets. | | | For compatibility (and common sense) the minimum packet size used with IP datagrams is 28 octets, which is 20 (minimum IP header) + 8 (LLC+SNAP header) = 28 octets (not including the MAC header). | | | The minimum packet size used with ARP is 24 octets, which is 20 (ARP with 2 octet hardware addresses and 4 octet protocol addresses) + 8 (LLC+SNAP header) = 24 octets (not including the MAC header). |
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http://www.ietf.org/rfc/rfc1042.txt
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| | Ethernet Frame Formats: |
| | The special SAP number of 0xAA was assigned to indicate that there are further headers after the 802.2 header that must be parsed to determine the network level protocol. | | | The first two bytes in this header (for this format) are always hexadecimal FF FF. | | | In Novell's 802.3 Raw format, the Data field begins with IPX header information. |
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http://www.geocities.com/SiliconValley/Haven/4824/ethernet.html
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| | Reference for NETBuilder Family Software Version 11.0 |
| | IPX data packets are encapsulated in the IEEE 802.3 header followed by IEEE 802.2 (LLC) header. | | | The default header format for Ethernet is IEEE 802.3. | | | The NETnumber parameter specifies the IPX network number assigned to a port and determines the header format to be used by that port. |
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http://support.3com.com/infodeli/tools/bridrout/u_guides/html/nb110/family/ref/ipx11.htm
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| | manquery - -s 7d sxp @ Eastern Illinois University |
| | For an LLC device, the LLC and MAC headers are prepended, and for a MAC device only the MAC header is prepended. | | | The DSAP and SSAP fields of the 802.2 LLC header are both set to the value 170, indicating a SNAP message and a MAC frame_type of LLC. | | | As defined by Rockwell, the SL_RAW ioctl puts the stream into raw mode, similar to the DLIOCRAW ioctl except that the frame-type field of the MAC header is considered to be a long word instead of a byte, preserving alignment. |
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http://www.eiu.edu/cgi-bin/manquery?sxp(7d)
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| | [No title] |
| | + * + * "off_mac" is the offset of the Ethernet header, + * which is 2 bytes past the ATM pseudo-header + * (skipping the pseudo-header and 2-byte LE Client + * field). | | | + */ +static u_int off_mac; + +/* * "off_linktype" is the offset to information in the link-layer header * giving the packet type. | | | */ -static u_int off_msg_type; +static u_int off_payload; /* * These are offsets to the beginning of the network-layer header. |
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http://www.tcpdump.org/cgi-bin/cvsweb/libpcap/gencode.c?r1=1.178&r2=1.179
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| | CVS log for tcpdump/print-llc.c |
| | There's no link-layer header on Linux ARPHRD_ATM packets; there's apparently (as per the previous version of this code) either an 802.2 LLC header (as per RFC 1483 and RFC 2225), or there's no header at all, and just an IP packet. | | | In addition, for packets with an LLC header, we should call the LLC printer, rather than assuming that it's SNAP-encapsulated (RFC 1483 says they're not always SNAP-encapsulated) and printing the header ourselves. | | | Only dissect UI frames as BPDUs, and pass the BPDU dissector a pointer to the beginning of the BPDU, not the beginning of the LLC header - not all BPDUs are encapsulated in LLC headers. |
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http://www.tcpdump.org/cgi-bin/cvsweb/tcpdump/print-llc.c
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| | RFC 1390 (rfc1390) |
| | The SNAP must be used with an Organization Code indicating that the SNAP header contains the EtherType code (as listed in Assigned Numbers [13]). | | | However, in order to allow future extensions to the MAC header and frame status fields, it is desirable to reserve additional space for MAC overhead. | | | This provides for 4096 octets of data and 256 octets of headers at the network layer and above. |
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http://www.cse.ohio-state.edu/cgi-bin/rfc/rfc1390.html
(2691 words)
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| | [No title] |
| | + * + * XXX - same variable-length header problem; at least + * the Prism header is fixed-length. | | | + * + * The header is 144 bytes long. | | | We + * assume a 24-byte link-layer header, as appears in + * data frames in networks with no bridges. |
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http://www.ackley.net/~jason/libpcap.patch
(6287 words)
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| | [No title] |
| | In Ethernet 802.3 the Frame Length field contains a value less than 1500 decimal (05DCh) and the first two bytes of Data must contain FFh. | | | 802.3 Header ** Frame Length / ** Data (always FFFFh). | | | 802.3 Header ** Frame Length / * DSAP (always AAh) \ * SSAP (always AAh) |
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http://www.connectotel.com/netware/frame.txt
(553 words)
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| | ComponentArt Snap for ASP.net |
| | I was able to quickly and easily create dynamic layouts, program customizable header templates, and build an extremely intuitive user interface. | | | Fully Customizable Any design can be implemented through custom header, footer, and content templates. | | | Flexible The Snap control can be incorporated into existing ASP.NET websites, and does not require users to be logged in. |
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http://www.componentart.com/snap/default.aspx
(184 words)
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| | Cisco - Understanding and Configuring VLAN Trunk Protocol (VTP) |
| | In that case, the ISL header and Cyclic Redundancy Check (CRC) would be replaced by dot1q tagging. | | | The format of the VTP header can vary based on the type of VTP message. | | | However, they all contain these fields in the header: |
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http://www.cisco.com/warp/public/473/21.html
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| | NETBOOK - Q & A on Types of Ethernet |
| | You describe two forms of Ethernet: one with a MAC type field in the header and one using 802.2-llc (a llc/snap-header). | | | The term "Ethernet SNAP" refers to the LLC/SNAP header defined by the 802.2 standard. | | | IEEE standard 802.2 specifies Logical Link Control (LLC) layer, and is an alternative to having a type field in the header. |
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http://www.netbook.cs.purdue.edu/othrpags/qanda25.htm
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| | Section Télécommunications |
| | I summarized here most of the frame format used in the networking world. | | | expands the 802.2 header to include the EtherType field that is necessary for | | | The Sub Network Access Protocol (SNAP) header is used to provide |
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http://www.eif.ch/~buntschu/doc/frame-description
(429 words)
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| | Don’t tempt potential hackers! Hide your Windows Web server with ServerMask |
| | The software provides control over what Server header data, if any, is visible in HTTP responses. | | | Dig Further: cookie, headers, web server, apache, php, firewall, scripting, iis, application server, snap, header, customization, perl, isapi filter, cookies, banner | | | ServerMask 2.0 can emulate the Apache Web server’s HTTP header order and disable Microsoft WebDav with one click to suppress its multiple identifiable headers. |
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http://www.waredig.com/download/2/detail_6966.html
(176 words)
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| | Web Page Hosting : psnap : 2.0.39 |
| | static struct datalink_proto *snap_dl = NULL; /* 802.2 DL for SNAP */ | | | * Find a snap client by matching the 5 bytes. | | | * Put a SNAP header on a frame and pass to 802.2 |
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http://www.oxxus.net/host/2.0.39/hosting-psnap.htm
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| | [No title] |
| | If the * msg opcode is SNAP_SENDWITHREPLY then no ack is expected for * the final window (the eventual reply will serve as a positive * ack for the entire window, or the lack of a reply will cause * the entire last window to be retransmitted). | | | = SNAP_KEYLEN) j = 0; sum += msg[i] & 0x0FF; } sum &= 0x0FFFFFF; DBGMSG (MSG,("DecryptAndChecksum - checksum result: %ld", sum)); return (sum); } /* * Build a standard SNAP header for an outgoing message. | | | * * Each fragment of a message carries a complete SNAP header, * but the sequence number is the same for each fragment in * the message. |
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http://www.cs.cmu.edu/~AUIS/ftp/web/ftp/src/contrib/snap2/snap2t/snptxmit.c
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| | ComponentArt - Product Forums |
| | I'm looking to have a header row with a select entry inside of it. | | | Issue with Snap Control Header and Select Tag | | | After seeing the demo with the expanding and collapsing control that has a header row and body content, I wanted to do something similar. |
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http://www.componentart.com/forums/ShowPost.aspx?PostID=4218
(340 words)
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| | SNAP header problems with multiple EtherLink 16 |
| | The AUTOEXEC.NCF file can now find and execute APPBIND.NCF. | | | Normally, a NetWare server's AUTOEXEC.NCF file includes multiple LOAD statements for each EtherLink 16, followed by multiple BIND statements for each protocol being used. | | | A problem occurs when multiple EtherLink 16 (3C507) adapters are installed in a NetWare 3.11 file server and multiple frame types (specifically Macintosh services with SNAP frame types, in conjunction with 802.3 or Type II frames) are bound to the adapters. |
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http://support.3com.com/infodeli/inotes/techtran/49a2_5ea.htm
(226 words)
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| | [No title] |
| | ¡( d d ðH ð ð0 “ ”Þ½h ¿ ÿ ? ð ÿÿÿ T¨ 3f Ì 3fÌ Ìÿ áá· îµ ï e ð] ð ðõ ð( ð ð ðÇ ¢ ð ð0 ÀÜ:¿ ¿ À ÿ ð (´ ðg ¨ Comparison of Both Schemes ¡0 ( 2 $ 3fÌþ $ 3fÌþ ðî ¢ ð ð0 Lè:¿ ¿ À ÿ ð ð ð ¨ Sharing a VC limits the number of VCs required in an IP & multi-protocol environment However, it uses an additional 8 Byte per AAL frame as a header. | | | Also an LLC/SNAP entity must be present at each endpoint to demultiplex the frames & pass them up to the higher layer protocol VC-based multiplexing is more efficient from a pure VC perspective. | | | ¨ ATM Switch ¡ 2 割 ð ð0 èÚ¸ ¿ ¿ À ÿ ð p ` à G ðG ¨ Different Protocols ¡ 2 ð ¢ ð ð0 L£¸ ¿ ¿ À ÿ ð ÀP à ðM ¨ Scenario: ¡( 2 ÿ3 þ ÿ3 þ ðH ð ð0 “ ”Þ½h ¿ ÿ ? ð ÿÿÿ Ì 33Ì ÌÌÿ ²²² î7 ï ç ðß ` ð & ' ðw ð( ð ð ð` ¢ ð ð0 ¨ :¿ ¿ À ÿ ð @v, ð ¨t ANSWER 1: LLC/SNAP ENCAPSULATION Share a VC using LOGICAL LINK CONTROL (LLC) Subnetwork Access Protocol (SNAP). |
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http://www.ece.gatech.edu/research/labs/bwn/ee6609/notes/Chapter_8.ppt
(1078 words)
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| | Snap - Wikipedia, the free encyclopedia |
| | S.N.A.P (Scaleable Node Address Protocol) - a generic, free and open network protocol designed primarily for home automation and control systems. | | | This is a disambiguation page, a list of pages that otherwise might share the same title. | | | Snap fastener, a term for a special type of fastner on a piece of clothing. |
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http://en.wikipedia.org/wiki/Snap
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| | IEEE 802.2 LLC |
| | SNAP is the layer between the Network layer and the MAC layer. | | | The LLC indicates if there is a SNAP header. | | | The main usage for SNAP/LLC is in Apple Macintosh networks using the AppleTalk protocol. |
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http://ckp.made-it.com/ieee8022.html
(303 words)
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