300-410 VPN Technologies Practice Question
A network engineer is configuring a site-to-site IPsec VPN between two Cisco IOS routers. The engineer wants to ensure that the VPN tunnel only comes up when there is interesting traffic matching an extended ACL. The ACL is defined as: access-list 100 permit ip 10.1.1.0 0.0.0.255 10.2.2.0 0.0.0.255. The crypto map is applied to interface GigabitEthernet0/0. Which command is required to complete the configuration so that the router considers traffic matching the ACL as interesting?
⚠ Common exam trap
Candidates often confuse the creation of the crypto map with the assignment of interesting traffic, assuming that defining the ACL alone is enough or that the peer command triggers the tunnel.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
match address 100
The match address command within the crypto map entry binds the extended ACL to the crypto map, designating the traffic that should be protected by IPsec. In this scenario, the ACL 100 defines the interesting traffic between the two subnets. Without this command, the router would not know which packets to encrypt and tunnel, and the VPN would not initiate as intended.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
match address 100
Why this is correct
Within the crypto map configuration, the match address command specifies the extended ACL that defines interesting traffic. This ACL determines which packets are encrypted and sent through the tunnel. Here, match address 100 tells the router that traffic between 10.1.1.0/24 and 10.2.2.0/24 should be protected by IPsec, triggering the tunnel when such traffic is encountered.
- ✗
crypto map mymap 10 ipsec-isakmp
Why it's wrong here
This command creates a crypto map entry and specifies that it uses IKE for IPsec, but it does not define which traffic is interesting. The match address command within the crypto map is required to associate the ACL with the crypto map entry. Without it, the router would not know which traffic should trigger the tunnel, and the VPN would not initiate correctly.
- ✗
crypto isakmp policy 10
Why it's wrong here
This command begins the configuration of an ISAKMP (IKE) policy, which defines parameters for phase 1 negotiations such as encryption and authentication. It is essential for establishing the VPN, but it does not specify which traffic is interesting. The question asks for the command that associates the ACL with the crypto map, so this is not the correct choice.
- ✗
set peer 203.0.113.2
Why it's wrong here
The set peer command identifies the remote IPsec peer's IP address, which is necessary for the tunnel but does not define interesting traffic. Without match address, the router lacks criteria to classify traffic as interesting, so the tunnel would not initiate based on the ACL. This command alone is insufficient to complete the configuration as described.
Visual reference
Quick reference
VPN Protocol Comparison
| Protocol | Port | Encryption | Authentication | Use Case |
|---|---|---|---|---|
| IKEv2 / IPsec | UDP 500 / 4500 | AES-256 | Certificates / PSK | Site-to-site & remote access |
| SSL / TLS VPN | TCP 443 | TLS 1.3 | Certificates / MFA | Clientless remote access |
| L2TP / IPsec | UDP 1701 | AES (IPsec) | PSK / Certificates | Legacy remote access |
| WireGuard | UDP 51820 | ChaCha20 | Public keys | Modern high-performance VPN |
| PPTP | TCP 1723 | MPPE (weak) | MS-CHAPv2 | Legacy — avoid in production |
PPTP is considered insecure. IKEv2/IPsec and SSL VPN are the current recommended options.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
This 300-410 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 300-410 exam.