Re: Packet retransmit questiion [7:69715]
First of all, I wouldn't post a question advertising it to be from the 350-001 test to a public newsgroup. It just seems like a bad idea. I'm responding to the question based on the fact that I took the test a couple weeks ago and didn't see the question. I'm HOPING that the question is from your study material for the test. Robert Perez wrote: > Hi all, > > I have a question on the CCIE 350-001 test. I have heard differing opinions > on this but when traffic crosses a WAN connection and there are problems who > does the retransmit?? Host or RTR?? Generally the sending host. > > 1.) In Frame relay there is a line hit or corrupt packet on the WAn, who > retransmits, should be the source router correct? Frame Relay includes a CRC to detect corrupted frames. The CRC is checked at the end router and is used to detect corrupted frames so that they can be dropped. Neither router will retransmit the frames, assuming of course that neither router is the source of the traffic. If one of the routers is sourcing the traffic, perhaps Telneting to the other router, then the routers would resend corrupted frames (actually the router would resend the IP packet, possibly resending multiple frames). But at this point the router is performing the role of a host. > > 2.) In a point to point circuit w/HDLC there is a line hit or corrupt packet > who retransmits, should be the source router correct?? > Same as Frame Relay. There is no link-level ACK, resends are the responsibility of the upper-layer protocols on the sending host. > 3.) In a bridged environment with a WAN a T-1 takes a line hit or corrupt > packet who retrnasmits, should be the source host correct?? > > Yes. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=69725&t=69715 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Packet retransmit questiion [7:69715]
At 6:46 PM + 5/28/03, Robert Perez wrote: >Hi all, > >I have a question on the CCIE 350-001 test. I have heard differing opinions >on this but when traffic crosses a WAN connection and there are problems who >does the retransmit?? Host or RTR?? > >1.) In Frame relay there is a line hit or corrupt packet on the WAn, who >retransmits, should be the source router correct? > >2.) In a point to point circuit w/HDLC there is a line hit or corrupt packet >who retransmits, should be the source router correct?? > >3.) In a bridged environment with a WAN a T-1 takes a line hit or corrupt >packet who retrnasmits, should be the source host correct?? In all cases, the host, if you are running IP protocols that even specify retransmission. TCP does, but UDP does not. RPC over UDP retransmits. The only exception where the router would retransmit would be if you are running X.25, LAP-B, SSCOP, or SDLC. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=69723&t=69715 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Packet retransmit questiion [7:69715]
Hi all, I have a question on the CCIE 350-001 test. I have heard differing opinions on this but when traffic crosses a WAN connection and there are problems who does the retransmit?? Host or RTR?? 1.) In Frame relay there is a line hit or corrupt packet on the WAn, who retransmits, should be the source router correct? 2.) In a point to point circuit w/HDLC there is a line hit or corrupt packet who retransmits, should be the source router correct?? 3.) In a bridged environment with a WAN a T-1 takes a line hit or corrupt packet who retrnasmits, should be the source host correct?? Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=69715&t=69715 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
