Hi Yang, 2015-08-21 14:46 GMT+02:00 Yang Luo <hslu...@gmail.com>:
> Hi list, > > I have updated Npcap to 0.04-r4. This version modified "Npcap Loopback > Adapter"'s MTU to 65536, so the maximum packet size is 65550 (65536 + > eth_hdr_size). > > But I found weird result in Wireshark's "Interface Details" dialog. > > 1) Npcap Loopback Adapter: > Transmit Buffer Space 1514 > Receive Buffer Space 1514 > Transmit Block Size 1 > Receive Block Size 1 > Maximum Packet Size 65550 > > Another Ethernet interface's result is normal: > 2) Ethernet0: > Transmit Buffer Space 1550336 > Receive Buffer Space 779264 > Transmit Block Size 1514 > Receive Block Size 1514 > Maximum Packet Size 1514 > > In Linux, Wireshark doesn't have an "Interface Details" dialog, so I can't > know what the expected result should be for a loopback interface. So I'd > like to know what these numbers are and is the result of Npcap Loopback > Adapter correct? It doesn't seem to affect the capture result. > > The latest installer is at: > https://svn.nmap.org/nmap-exp/yang/NPcap-LWF/npcap-nmap-0.04-r4.exe > > >From what I can see in the source code ( https://code.wireshark.org/review/gitweb?p=wireshark.git;a=blob;f=ui/gtk/capture_if_details_dlg_win32.c;h=76b264646c8cc5eaf1ead6c388d869caed3ccf2f;hb=refs/heads/master ) the info is populated by calling the following Winpcap interfaces: wpcap_packet_request_uint(adapter, OID_GEN_TRANSMIT_BUFFER_SPACE, &uint_value) wpcap_packet_request_uint(adapter, OID_GEN_RECEIVE_BUFFER_SPACE, &uint_value) wpcap_packet_request_uint(adapter, OID_GEN_TRANSMIT_BLOCK_SIZE , &uint_value) wpcap_packet_request_uint(adapter, OID_GEN_RECEIVE_BLOCK_SIZE, &uint_value) wpcap_packet_request_uint is a wrapper on top of wpcap_packet_request which is defined here: https://code.wireshark.org/review/gitweb?p=wireshark.git;a=blob;f=caputils/capture_wpcap_packet.c;h=5b3ffc479d3f4cfb0bfc78eb6ec0a820c39f2f9e;hb=refs/heads/master >From what I can see, it seems to be only used for this dialog. Note that the NDIS version also seems suspicious (it's reporting 5). Cheers, Pascal.
___________________________________________________________________________ Sent via: Wireshark-dev mailing list <wireshark-dev@wireshark.org> Archives: https://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-requ...@wireshark.org?subject=unsubscribe
