CN8812: Problem set 1
网络工程代写 All the switch ports have the data rate of 100 Mbps. The bridge IDs (BIDs) of these switches are related as follows:BID of S1 <BID of S2 < BID ···
1.The following LAN consists of five Ethernet switches: 网络工程代写
All the switch ports have the data rate of 100 Mbps. The bridge IDs (BIDs) of these switches are related as follows:
BID of S1 <BID of S2 < BID of S3 < BID of S4 < BID of S5.
Determine the following spanning-tree parameters:
- The designated cost for each segment;
- The root path cost for each bridge;
- The status of each port (blocking, designated, or root port);
- If segment 6 is broken, estimate the time it takes before the new spanning tree converges. Give detailed explanation.
- A bridge, whose Bridge ID is B5, has four 100-Mbps ports. Suppose it received the
following BPDUs from its ports:
- Port 1: RBID=B0, RPC=23, SBID=B1, SPort=1
- Port 2: RBID=B0, RPC=42, SBID=B2, SPort=2
- Port 3: RBID=B0, RPC=57, SBID=B3, SPort=3
- Port 4: RBID=B4, RPC=0, SBID=B4, SPort=4
Assume that $B0 < B1 < B2 < B3 < B4$.
- Determine the port priority vectors and the port roles of the ports
- If bridge 5 subsequently received a BPDU on port 2 containing the following
information:
RBID=B0, RPC=46, SBID=B2, SPort=2
Describe the reaction of bridge 5 if it is using
1.STP
2.RSTP
3.Consider the following LAN:
Assume that: 网络工程代写
B1_ID < B2_ID < B3_ID < B4_ID < B5_ID < B6_ID,
where Bn_ID is the bridge ID of Bn. Suppose a new link is established between B2 and B1, determine the time it takes for the new spanning tree to converge, if Rapid Spanning tree protocol is used. Assume that a BPDU takes a total of 0.5 sec to be generated, transmitted, received, and processed and that a bridge can transmit multiple BPDUs at the same time. Sketch the sequence of state changes and Proposal/Agreement BPDU exchanges among the bridges
4.A bridge configured with IGMP snooping received the following three IGMP packets at times t1, t2, t3 and t4, where t1 < t2 < t3 < t4:
- t=t1: IGMP_Join(225.135.1.1) received at port 3.
- t=t2: IGMP_Join(225.135.1.1) received at port 2.
- t=t3: IGMP_Join(225.135.1.1) received at port 2.
- t=t4: IGMP_Leave(225.135.1.1) received at port 2.
Describe the action to be taken by the bridge upon the reception of each of these packets.