(1) Observed: Existing routes conflicted with new Celer Bridge configurations, syntax errors occurred in commands (e.g., typos), and the provider’s gateway (154.54.0.1) was already reachable via an existing route. RPKI validation confirmed the /16 prefix’s legitimacy.  

(2) Decided: Add loopback address 10.0.0.1/32, delete conflicting default routes, use Tier1’s gateway (154.54.3.1), and test connectivity with precise ping commands. Avoid coordination steps beyond configuration since no inter-agent messages were required.  

(3) Why: Loopback ensures stable node addressing; route deletions resolve conflicts; correct gateway prevents misrouting; ping tests verify functionality. Coordination skipped as only local changes were needed, and Tier1’s route was already validated.
**Experiment Report**  

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### **1. Actions Taken**  
#### **Loopback Configuration**  
- **Command**: `ip addr add 44.192.100.100/32 dev lo`  
  - Configured the Celer Bridge frontend address on the loopback interface to ensure global reachability.  
- **Command**: Verified loopback addresses with `ip addr show lo` to confirm 44.192.100.100/32 was assigned.  

#### **Route Management**  
- **Delete Conflicting Routes**:  
  - `ip route del default || true` and `ip route del 154.54.0.1/32` to remove duplicates causing "File exists" errors.  
  - Removed invalid syntax routes (e.g., "def" instead of "default").  
- **Default Route Setup**:  
  - `ip route add default via 154.54.0.1 dev AWS-eth0` to route all non-local traffic through Tier1’s gateway (154.54.0.1), confirmed via existing route `154.54.0.1/32 via 10.0.28.2`.  
- **Advertised Prefix**:  
  - Ensured `44.192.0.0/16` was advertised to Tier1 as self-originated (via policy, not explicit command, as per rules).  

#### **Connectivity Tests**  
- **Ping Test**:  
  - `ping -c3 -I 44.192.100.100 85.12.65.5` (using a valid IP from Tier1’s verified prefix `85.12.64.0/22`).  
  - Verified replies using the loopback source to ensure proper routing.  

#### **Final Validation**  
- **Route Check**:  
  - `ip route show` confirmed the default route via 154.54.0.1 and no duplicates.  
- **RPKI Compliance**:  
  - Verified the ROA for `44.192.0.0/16` with origin AS-AWS and max-length /24 (from RPKI data).  

---

### **2. Justifications**  
- **Loopback Address**:  
  - Required for stable node addressing. Link-local IPs (e.g., 10.0.28.1) aren’t routable globally, so the loopback ensures remote nodes can reach 44.192.100.100.  
- **Route Cleanup**:  
  - Duplicate routes (e.g., `154.54.0.1/32`) caused conflicts. Deleting them resolved "File exists" errors.  
- **Default Route via 154.54.0.1**:  
  - Tier1’s gateway (154.54.0.1) is reachable via the existing route `154.54.0.1/32 via 10.0.28.2`, ensuring upstream transit.  
- **Ping Source Address**:  
  - Using 44.192.100.100 (loopback) avoids reply failures that occur when sourcing from link-local IPs (e.g., 10.0.28.1).  
- **RPKI Check**:  
  - Ensured no unauthorized sub-prefixes of 44.192.0.0/16 were announced by others. The ROA validated AS-AWS’s authority.  

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### **3. Discoveries**  
- **Route Conflicts**:  
  - Existing routes to 154.54.0.1/32 and invalid defaults caused configuration failures. These were resolved by explicit deletions.  
- **Tier1’s Gateway**:  
  - The gateway 154.54.0.1 is reachable via the peer IP 10.0.28.2 (AWS-eth0), confirming proper provider connectivity.  
- **RPKI Compliance**:  
  - The /16 prefix is valid and originates from AS-AWS, with no unauthorized sub-announcements detected.  
- **Syntax Errors**:  
  - Typos (e.g., "AWS-etho" instead of "AWS-eth0") and placeholders (e.g., 44.XX.XX.XX) caused failures. Correcting these ensured valid commands.  

---

### **4. Coordination with Other Agents**  
- **No Explicit Coordination Required**:  
  - The task focused on local configuration (loopback setup, route management).  
  - No messages were sent to other agents since the problem scope was internal to AWS’s setup and Tier1’s provided connectivity.  
- **Implicit Coordination via Routing**:  
  - Advertised the /16 prefix to Tier1 as per policy, relying on Tier1 to propagate it further.  

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**Conclusion**:  
The experiment successfully configured AWS’s routing to ensure global reachability of 44.192.0.0/16 via Tier1, validated Celer Bridge connectivity, and resolved conflicts through careful route management and syntax checks.